I am trapped by a friendship and don't know how to set myself free

Hey guys, this is my first post here. Which is funny I'm sharing this here since I usually have someone amazing I can tell this kind of things to, but this time I can't tell him because it's about him. My apologies if this post comes out as too long, but I feel like I have to post the story since the beginning.We met on Facebook. We'll call him Alex. He's from out of state and we had been friends on there for a long time. We had the same hobby and had a couple mutual acquaintances (which is why we added each other), but other than liking each other's posts every once in a while, we never really talked until around June last year when he messaged me on my birthday. Despite never having actually spoken, our conversation flowed like we had always known each other (After all we had been Facebook friends for over a year at that point). The connection was almost immediate. I was going through an emotionally turbulent time in my life, and suddenly finding a gay friend who was not only willing to listen but to help me as much as possible (He's a psychology major) truly felt like a blessing to me. I had always wanted to have a friend like that, and he came to my life in the time I needed him the most.We suddenly became "unofficial" best friends. We had never met in person, but he became the person I chatted with the most. We texted each other every day since the time we woke up until we went to bed. I had never had a friend like that in my life and I could not be any happier! I'm a very complex guy, but he understood me perfectly. For the first time in my life I had a friend with whom I had nothing to hide: my awkwardness, my imperfections, my insecurities. I felt fully comfortable telling him about everything; he always gave me excellent advice, and everything he did for me meant so much to me. He was the best friend I could ever ask for. It was because of his reassurance, because of his advice, and because of his support that I found the courage I always lacked to go out and start dating for the first time.When I finally found my first date I was so excited. I met Mike. He was just adorable and we agreed to hang out during the weekend! I could not wait to tell Alex about how happy I was!! Except when I finally did it, the reaction was not at all what I expected. He reacted with silence, which for him was extremely strange. I asked him if he was okay, and he said he needed some time to process the news. I was… shocked. He gave me the courage to go out and start dating for the first time and now he was acting just so strange. Admittedly sometimes I have a hard time controlling my emotions in moments like this, so I started to sort-of panic. Begging him to answer me, to at least say something. I started to get the hint of what caused his reaction, and told him it was just a date, that this does not change anything, and that I'm still going to be there for him.We had a long and deep phone conversation that night. Turns out he had bottled feelings for me all along and despite his support being the main reason I found the courage to date someone, me meeting Mike was the drop that spilled his cup. He was seeing someone at the time and I was totally shocked for him to tell me that, especially since he's the one who always talked to me about not bottling up my emotions. He had a breakdown that day and made me forget entirely about my date with Mike on the weekend while I talked to him. I consoled him. Once again I told him it was only a date, that it's because of him that I gathered the guts to do it, and that his friendship and his advice had given me the strength to finally get out of the hole I was stuck in. My voice was being as compassionate and sympathetic as possible, but on the inside I was already a mess. I was not ready for such a plot twist in the highest milestone of my pretty pitiful social life (getting my first date at 21), and my emotional instability was not helping at the moment. Alex was the one I went to when I had situations like this, but who do I go to when I need advice about him? Once again I felt alone.The day of my first date came and if there's ever a time when I felt like I was in an emotional roller coaster, it was then. There I was, having the most wonderful time of my life finally feeling the magic of having a mutual attraction with someone and trying to enjoy every second of it, while my phone kept vibrating with messages from Alex telling me how much he felt for me all this time and that he had no idea why he didn't tell me before and that he now regrets it. I never felt more overwhelmed by so many different emotions at the same time, and I had a rather hard time coping with them. After a wonderful dinner Mike and I ended up going to my place for the night. I wanted to enjoy the moment so I muted my phone and started watching old Disney movies with him as things started to happen little by little. Things were finally happening and it was supposed to be the most wonderful night of my life, but all I could feel inside me was… guilt. And shame. I woke up during the night and went to the bathroom to check my phone. I had no less than 10 missed calls from Alex and over 30 messages from him on Facebook, iMessage, Whatsapp, and even Skype. I could not handle it anymore and started to cry on the floor. He's my best friend, the one who helped me so much to overcome my insecurities more than any other friend I had, the one I had so much affection for despite never having met him in person and whose friendship I valued immensely but to whom I was just never attracted to. He was never my crush, he was the friend who was always there for me when I talked to about MY crushes (and he would always tell me about his crushes, exes, and experiences) and who always gave me advice to get closer to them, but once I finally found someone it all collapsed. This was in mid-October 2015 and to this day I still feel awful I made him feel that way, but at the same time I don't want to feel tied up to not trying new things, become more social, and find love out of fear of breaking his heart. I didn't tell him the details about my night with Mike. I did not want him to have a bigger meltdown, and for the first time since I met him, I felt like I couldn't open up to him as I used to do anymore. That's when our friendship started deteriorating.Mike became my first boyfriend, and I started seeing him almost on a daily basis. Sometimes I would just lie to Alex and tell him I was busy doing homework or studying for a quiz when in reality we were cuddling and making out in my couch. Other times I told him I was hanging out with Mike, but never went in details about our intimacy. Usually he'd just be okay with it but I'm sure he was just playing along. Every time I talked to him I felt like I needed to hide more and more stuff from him. Sometimes I would need relationship advice and had nostalgia of the days when he used to advise me about anything. I wished I could still count on him and despite he repeatedly saying nothing had changed in the way he's always there for me, I knew that now I had to be careful about what I told him, and every time I opened his texts I always felt an overwhelming sense of anxiety and nervousness. But I didn't want to lose his friendship.He kept telling me how he wanted to come see me, to hug me, to kiss me, and explore every inch of my body, but every time he made those type of comments I become more and more overwhelmed with guilt and anxiety. Most times I did not know how to reply and would just give a generic response like "wow, I'm so flattered". He asked me more than once if there was a good time in the next few weeks for him to come and "just hang out", but I had to lie to him and tell him I was just very busy with school and just didn't have the time. I wasn't going to tell him that I was just not mentally stable and ready to see him after the events of the couple weeks prior. Having him fly over at that point would've been a terrible idea.One day in mid-November I woke up a post on my Facebook timeline. He was making a clear reference to my two favorite songs and he added his hometown airport as location. He didn't tag me or anything, but I instantly knew what was going on and that this wasn't a coincidence. He was coming here. Despite me telling him repeatedly it's not a good time to come, I knew he was on his way. The realization hit me immediately and I had a mental breakdown. Was he going to show up at my doorstep? (Unlikely since he didn't know with exactitude where I lived) What is he planning to do? How am I going to cope with it, especially when having Mike around?! I began to cry and panic and just repeat "No no no no this can't be happening" over and over again. Seeing Alex a couple months ago would've been almost like a dream come true, but at that point it was about the last thing I needed. I did not want to get Mike involved in this and did not have anyone to ask for advice, and since he never once told me he was coming or that he was even here (when he landed here all he said was "Hey, how are you?"), I realized I don't have the coping skills necessary to deal with that situation, so I decided to just disconnect from all social media for that weekend. I still extremely guilty for doing it, but I had no idea how to cope with it and just acted compulsively.I did not see him that weekend. I was honestly upset at him for not listening to me when I repeatedly asked him not to do the exact thing he did. My reaction was compulsive, but so was his action by putting me in that situation especially when he knew I was not expecting it and it came out of nowhere. That was the last time we spoke for a long time. At first it was the overwhelming mix of anxiety, awkwardness, anger, helplessness, and confusion feelings. But after a while what kept me from reaching out to him was the feeling of guilt and shame for acting the way I did. I did not know how to apologize, how to make it up, how to even approach him. He kept sending me messages every week or two and even wrote me poems, but every time I got a message from him I felt more and more guilty and all I wanted to do was cry. I just did not know how to respond.I finally gathered the courage to reach out to him sometime last month. I opened up to him and sent him a long and emotional message apologizing for my actions (or more accurately, reactions) and how I let our friendship deteriorate so much. I missed him so much and wanted to be best friends again like we used to be. He answered back quickly and that night we had a long phone call where we apologized to each other and caught up with our lives. And surprise surprise, he was offered a position as research assistant at his university's campus in my city and was moving here starting August. I wanted to start over again. By the way, I should note that by that time I was no longer dating Mike. We always had a wonderful time when we were together and we were happy, but it just didn't work out and we broke up in good terms. This was in in February and I reached out to Alex in March. He never once asked me about Mike though. I am sure he was avoiding the topic on purpose, because I would've done the same as well. Either way, I was truly happy to have him back and once again be able to talk to him about my life.We started talking every day again, the same way we used to do. He told me he had some airline miles he could use to redeem a flight here. I thought it was long overdue to finally meet him in person, and since I had a free weekend coming up soon, we decided to finally make it happen. I was truly excited and the day finally came some three weeks ago. He arrived with a big stuffed Toothless plush, which he knew I loved. We gave each other a long, tight hug and had a night together. We got dinner, went to watch a movie, it was great to finally be able to hang out with Alex. I was worried this would happen, but back at home one thing led to another and we ended up in pure intimacy. We started by cuddling, then kiss, and so on. While at times I was certainly aroused and enjoyed the sensation, other times I could not help but feel extreme guilt of what I was letting happen. But he seemed so happy, and I want to make him happy, so I did nothing to stop things and kept on. In retrospective this might have been a bad idea, but at that moment I felt like it was my way of making up to him for how I had acted in the previous months. He kept whispering in my ear how much this meant to him, how he had always wanted it, that he loves my body, that he's obsessed with me, thanking me for letting him get to know me intimately, and all types of overwhelming comments that every time he mentioned just made me think "Please don't say that, please don't say that" over and over again. I obviously did not feel the same way, and that made me feel really guilty.Right after he left I sent him a long text explaining to him that I'd like to keep our relationship where it's at, not wanting to give him the hopes that I want something more than a strong friendship with him, and that if we now just crossed the line into friends-with-benefits, I'd like to keep it that way. Especially now that he's going to be moving into my city, I wanted to leave it clear. Fortunately he took it well and told me that as much as he'd like to be more than friends, he'll respect my decision. This made me really happy that he took it so well.However, now it seems like he has taken the FWB thing way too serious. He's always telling me how all he wants to do is cuddle with me, how he can't wait to see me again, how that's what he's always thinking about, and again I just keep thinking "Please don't say that". I can't help but feel guilty once again, and I don't know how to answer when he says those things so I just say stuff like "I miss you too :)" because I can't find a way to express how I truly feel: Overwhelmed. Overwhelmed by all the constant compliments, comments, details, and flirts. There's no reason why this should be a bad thing. Never imagined there would be such thing as overwhelming affection, but I feel like that's what is happening right now and it's making me feel terrible about myself. He is trying is best to make me feel good about myself with constant compliments, but every time I just feel worse.How do I leave it clear that although his wonderful friendship is one of the bonds I value the most and I love him dearly, but I am just not attracted to him and I don't want to be in a relationship with him? He is obsessed with me, and I want to start dating again, but I can't help but feel like if I start doing it again it will just wreck our relationship once again. I don't want to lose him, but I don't want to feel tied in my love life by the fear of hurting him.I feel trapped, and I don't know what to do. Looking for advice from some of you, perhaps you have been in a similar situation and might be able to give me a little insight in how to approach a situation like this. I would appreciate that so much! Like I said at the beginning, I usually have someone to ask for advice, but this time it's about that person.Thank you! - NachoTL.DR: My best friend gave me the strength to start dating, but once I started dating he confessed he's obsessed with me. This damaged our relationship for months and now that we're friends again I want to go back to dating but he still has strong feelings for me and I fear losing his friendship again. I feel trapped.