Will this ever be right?

If I don't get this off my chest I will never be able to sleep again. Though, I don't even know where to begin. I would just call my best friend but I bother her far too much with my troubles as it is. I also made her swear to never say anything negative about my relationship again, because at the time I didn't want to hear it. I have been in this predicament for about four years now. I met this boy when I was about 16, it was the whole perfect first love thing. We were inseparable, for about a year. Then we both got tired of the whole controlling, attached at the hip deal. So we broke up right after junior prom. I was devastated. I couldn’t eat for about 2 weeks. It was pathetic. We started talking again when school started, and my parents were completely against it. We dated again. Broke up again, this time after he had already begun talking to some girl at his work, which was also devastating after I found out later. He swears he never actually cheated but that’s all bullshit. Later we became friends again. All this time he is seeing different people but saying he is in love with this girl from his work. I was still in love with him. I had to hear him cry over her, and say “God is punishing me for talking to her, she is the most beautiful thing I have ever laid eyes on, I can’t have her she is dating some guy…”this basically made me want to end my life right there. I begin to think talking to him was okay and I would get over it, it felt better than not having him in my life. Then we began to use each other for obvious reasons, he couldn’t have her and I didn’t want anyone else. It made me feel horrible but I couldn’t stop. I never really got serious with anyone else because I was so involved with him. Eventually we stopped and he started dating lots of other girls. He “fell in love” with some girl from myspace. She basically broke his heart, he realized “he never really loved her” (bullshit… he was just mad) Later to mention he “screwed up…and was sooo sorry” he’d had sex with her. After this he realized he missed me and couldn’t live without me (even though he NEVER really did…because I was an idiot) He stopped talking about the girl from his work. Said they never did anything, but he was so crazy about her? I’ll never believe him, I want to kill her. I have never had sex with anyone else and that just seems pathetic to me now that he suckered me into being engaged. 6 months ago when we first got back together everything seemed great, now I have so much regret. I wish I would have asked him to never call me again when he bothered me about his relationships. I had to hear how much he loved her and it makes me sick. I feel like the things we do together do not even compare to the way he was with those other girls. Basically I am Pissed! Mostly at myself for not trying to make it work with someone else, but it just seemed like no one else compared. I don’t mean to make it sound like I am the only person that got treated wrongly because at one point in there I was dating his use-to-be best friend (who was a complete goob so it didn’t last very long) Also I told everyone he was gay when we broke up the first time. Most people believed it. It seems like a few months ago I had let everything go. We were fine and I was happy, even my friend that hates him said I was happier than I had been in a long time. I don’t know what’s wrong. I feel bipolar and alone. I have a lot of free time and he has a new job that takes up most of his time maybe that is why all of these feelings are coming out of nowhere. Anyways it seems like marring him is all I have ever wanted and now I am just angry because it seems like I am just a safe bet. He treats me fine, that’s not the problem. I just want more out of a relationship now than fine. I want to impact a life so much that they could never leave, the same way I feel about him. I am tired of being the one to chase instead of being chased. I just don’t know if I can be happy for the rest of my life not knowing if it is possible for me to love someone else because I have never tried. Right now that makes me feel pretty selfish. He said letting us fall apart was the biggest mistake ever, but I think it would have happened anyway, even if wouldn’t have talked to someone else. I feel so immature because that was so long ago, but I have a hatred for her that will never stop and I hate the place he use to work. I don’t know if I can ever trust him the way people are suppose to, my tolerance for him and his lies comes and goes. I just want to be happy again and stop being so emotional. I am tired of yelling at him for stupid things because I am suppressing all of this anger inside. Any advice?... I wish I could just leave for a while