Devastated

Hi, r/gay. I apologize in advance for the sheer negativity of this post, but I felt like I needed a place to vent.I am a 26 year old gay male, who has been comfortable with his sexuality for about 10 years now, and is generally out to family and friends. While I consider myself to be a person who likes to experiment with sexuality (I have casual sex every now and then, I think it is a nice thing to do as long as you protect yourself), the one thing I want the most in life is a loving, monogamous, healthy relationship. I want to feel the butterflies, I want to look forward to seeing the person, and I want the good morning texts, the romantic dinners, the trips together, the whole thing. Besides, I am relatively confident in my good qualities (I am relatively good and young-looking, have financial/job security, etc.). I don't constantly obsess about this, but we all feel lonely sometimes, and especially after this, the feeling became just overwhelming.Professionally, 2016 couldn't have been a better year for me. I quit my office job, became a freelancer doing what I love and making a lot more money, with the added bonus of not being tied to any particular place or boss. However, in terms of relationships, it continued the nightmare that has been my love life. The truth is, I have never been in a happy relationship. My entire life has been a series of falling in love (with varying degrees of intensity), maybe hanging out a bit with said person, only to have some disagreement or fallout that leaves me alone. I have only had one real relationship, back in 2014. I dated a friend who I wasn't in love with, thinking he would grow on me. After 8 months, I ended it and we are friends now.Last spring/summer I had a few dates with a guy I was really into. He was my age, very attractive and smart, and we went as far as cuddling together. Eventually, he kept sending mixed messages and when I confronted him, he said he was not ready for a relationship and didn't see me that way (he still had some unresolved feelings with his ex). So I walked away.In October, I met a guy on Tinder, substantially younger than me (college student). While the age difference made me a bit wary, he didn't seem to mind (has a preference for older men). Plus he was very funny and mature-sounding for his age. Before I left (I was going to travel abroad), we spent an afternoon together. The food was great, so was our walk together, the sex was pretty fucking great, and we became friends and talked on a regular basis, every day after that. He would tell me about his daily life and studies (nursing) and I would show him the places I was visiting. We also continued to be sexually very intimate, but, it is very important to note, we were not anything besides friends. I don't want to go into more details as the story gets pretty long, but in December he asked me if it would be okay to see other people, and I said that I couldn't force him not to see other people. Which is when he revealed to me he was already seeing someone else. At the time, I wished him the best, but I got jealous and couldn't figure why. So that is when I realized I was actually in love with him. I confessed my feelings, and he said he was sorry but didn't feel that way for me anymore. This was devastating for me, even more so happening just before Christmas.Earlier this month I came back and he waited for me at the airport. I bought him dinner and brought him a teddy bear (which I knew he liked), I stayed at his place that night, but I could tell he was absolutely disinterested in me. So, a few days later, I cut all contact with him and haven't spoken to the guy since (he lied to me about somethings and I decided I didn't want that for me). Last I checked, he and the guy he was dating had a fight. While I am not sure if they are even together anymore, I decided to absolutely let go of pursuing him.He made me feel things I absolutely thought I would never feel again. I started having these anxiety attacks, heart beating very fast, stomach feeling like shit, feeling of desperation. I haven't felt this since one other guy that I liked, back in 2011. I suppose it is because I felt like I had "let go" of an opportunity (i.e. it's not that he never liked me, it's that he had liked me before and I missed the chance).So in summary, I am absolutely defeated at this point. I keep going about my daily work and tasks and try to get on with my life, but I feel devastated and suicidal (I have had suicidal thoughts since my early teens, and they sometimes come creeping back). I am doing workouts to help with the anxiety, but when I go back to my desk to work I switch between compulsive crying and anxiety (the crying really is the less awful option here). I feel like I fucked up so badly nobody wants to be with me. I do believe that everything happens for a reason, but I am not sure what the reason is for things being this way.Does anyone else feel like this? I have tried and keep trying all the dating apps: grindr, tinder, happn, scruff, hornet, match, OKcupid. All very different and with different kinds of people, but nothing has worked for me so far. Right now, I feel as though I may never be in a fulfilling relationship, and to be honest, I don't even feel like looking for one. I can't imagine myself being happy with anyone at this point. I know that I will feel better in a few weeks or months, but I am absolutely dreading the thought of things not working again, of going through this cycle again. I feel like I've exhausted all my strength.Sorry for the long post. You're absolutely free to ask me anything you like.PS.: For those into astrology, I am a Pisces.