Should I tell him?

THIS IS A LONG READ AND KIND OF A RANT SO YOU DONT HAVE TO READ THE WHOLE THING BUT IT WOULD BE APPRECIATED!So something is really bothering me A LOT. I am bisexual but I have had really strong feelings for my best friend for like 2 years.....basically since my senior year. His family helped me out a lot during a rough time in my life, (my brother almost died, but he is fine now) and my parents stayed in the hospital while I stayed at my friends house for a few weeks. My friend, who we will call C made me laugh and feel a lot better during the time I was feeling down, he always cheered me up even if he didn't try, he was just fun to be around. Anyways I left, went back home and started realizing I missed him and two months later realized I liked him. I fell for him, which is funny because I never found him attractive or loved him before, just as a friend. A couple years passed, he says he is straight but I still like even more than before.....it sucks, and I'm tired of hiding how I feel about him, it almost hurts to be around him. It's hard when he starts talking about girls and checking them out, I get kinda mad, I feel like he led me on my senior year. At one point I actually thought he liked me, he said he Loved me multiple times during high school, like I would call him and right before I would hang up he would say wait and pause for awhile and say I love you and do a nervous little laugh and hang up. He did that three times. Another time we were talking about prom and who we were taking and I said no one and so did he. And then he started to say "do you wanna......(long pause) never mind." At a little goodbye party for a friend C led me on again. Making it a point to always sit next to me and follow me, hell I went outside to take a piss and he followed me and watched me and made a stupid joke. We held hands too for a couple seconds. Like he would flip he off and I would grab his finger and we ended up holding hands somehow and we looked at eachother and smiled and he held tighter for a couple seconds, then slowly let go. Another thing I did that day was ask what he would do if my face just magically appeared in front of his, as we were across the room, and he said he would kiss me and laughed. All of this happened in front of our friends, except the pissing part.We hang out all the time still, which makes it really hard on me btw.Now he says he is straight, he has never had a gf but has gotten with a couple. I told him I'm bi and he was cool with it and said he was thinking about becoming bi. I said it's not really a choice, and he said that makes sense, and that he is straight. Now I really want to tell him how I feel, it's eating me alive, like I can't sleep at night sometimes. Should I tell him and if so how? It's like a lose lose situation for me. I don't want to ruin out friendship but then again this feeling of hiding my feelings really sucks so WHAT THE HELL DO I DO? And do u guys think there is a chance he might be bi and not know it? Thanks!