stuck between a rock and a hard place

Hey guys. So I've been with my boyfriend for almost 11 months now and I really care about him a lot. We've been friends since 6th grade so we know everything about each other. Sometimes we fight but we eventually get over it, some arguments take longer to make up than others. But one thing that has been happened G for a while now is my other friend. Let's call him nick. So nick and I have been friends for a few years now and it wasn't until a couple moths ago that he told me he liked me. I told him that nothing with us would happen because I had my boyfriend. He accepted that and we were just friends. The problem is that i liked him. Obviously since he liked me and I turned him down he stopped talking to me for a couple moths but then came back and did that one more time. Both times he's told me how much he likes me and how well he would treat me. I do like Nick but I don't want to hurt or leave my boyfriend. I'm not going to cheat I just don't know what to do. Another thing is my boyfriend has some pretty intense anger issues, he says he would never hit me but with some past abuse issues with my mother when he's angry and goes to touch his hair I'll flinch. I just don't know what to do. I need some advice. Anything will help