Still haven't let go

I honestly don't know why, but I haven't let him go. I ended up moving back with him after being on my own for five months. It was a mistake from the start. He isn't good to me. And maybe I'm not good to him either. Neither of us wants to give it all because we know how much we can hurt each other. I'm so confused. Sometimes I want to really give it my all, but most of the time I'm too scared. I've made a lot of progress, I can avoid his calls and I can keep from calling him. I can deal with our arguments in a more constructive way. But it takes two to make it work. He is slowly improving as well, I can see. However, I can't stand being hurt anymore. I can't stand another ugly fight. Even if I were certain that in the end it would pay off, I don't want to spend another year in a cycle of pain and pleasure. I'm learning to love him less. Everytime he does something to make me feel insignificant, I let go of him a little. I'm so scared of leaving but I'm also afriad of staying and feeling the ugly emotions that revisit each time we fight. I'm starting to see how much it affects me and how silly it is to give this relationship even one more day.  We're both good people and we have a lot to offer, but we shouldn't be together if we hurt each other so much. I wish I could understand him better. I wish I could understand myself better. I also wish this relationship hadn't been so painful but I know or at least I hope someday I will see the point.