Is there anyway to get over what happened or am I always going to feel this pain. (Sorry, it's long)?

In April of last year, my boyfriend who I had been dating for eight months cheated on me with someone behind my back. He dated her for about a month, and I literally had to drag myself through each day after I found out. I even tried to date someone else, and it didn't work. I ended up hurting that person because of my own selfish needs of relief from the heartache. Him and his new girlfriend would both call me names like.. "fat b*tch" and would make fun of me, because I would tell him how much I loved/missed him. I felt pathetic, and they only made it more obvious. I compelled myself away from him, which only made me even more messed up. I tried the best to forget about him. I couldn't. It took a long time to even work up the sense to talk to him again. It had been awhile and I fell in love all over again. I felt so stupid, but I really needed him. I had tried so hard to find new people and it just didn't work. He even was single for awhile so I wouldn't feel like I was just filling in the other girls spot. And, yes I give second chances. So please don't think anything bad of it.. Thing is I can't stop thinking about what he did to me. When we started dating again, it slowly began to excel back into a strong relationship. It's not been over a year since we got together, and we're perfectly fine. Except for the fact that I have this overwhelming feeling every single day.. I feel like the pain is still there. I guess I should suck it up since it was a long time ago, but it's almost impossible to get past it. It doesn't affect our relationship, but it definitely effects me. I've even thought about wanting to just.. end my life. But that makes me feel even worse, because of the things it'd do to my family/friends and my boyfriend. I mean, people go through way worse than I do.. I don't know why I think about it. There's nothing wrong with my life. I feel selfish. I find myself trying to find ways out of talking with him so I can just cry, and not have to bring it up in front of him, when he asks what's wrong. I really just want it to go away, but I don't want to leave him after all we've been through.. Talking to him about it makes it worse, so I don't know what to do anymore. Please, what should I do to ignore/forget this feeling? I feel like this traumatic event in my life has killed me emotionally. I've tried so hard to forget this.