I Keep Saying No

So long story here. I'll try to summarize.

I started dating my boyfriend the summer before my senior year in high school. I've been with my boyfriend for almost 6 years. We were engaged for most of them. At first, we did the deed quite a lot--about 7 times in one weekend once back then.

About a year into the relationship, before I started college, sex started to hurt. I figured it was from doing it too much, or birth control (depo at the time), or depression from my ex raping me (once).

So, we'd try once or twice a month to do stuff, until it hurt, or I told him to keep going since he'd already started.

Eventually the time between attempts got longer. Before last weekend, the last time we'd tried (successfully) was in December.

I graduated college last year, so the only stress I should have is making myself go to bed on time before work the next day. Not deadlines and classes.

But I always find myself telling him I'm not in the mood. At first, I thought it was fear of pain during sex. I didnt want to get hurt. If I spent the first few minutes worrying, then of course it would hurt. But I cant make myself relax.

And I've since told him this: I cheated on him twice with another guy. Pretty much everyone knows. Both nights were after drinking, but we were sober enough to decide i was spending the night. The guy did all the work. I felt safe with him, relaxed, basically like a single, 20-something you see in movies (not trying to glamorize it, I swear). Anyway, i wasnt thinking of Bills, pain, etc. I was comfortable with this dude who made a move on me each time (he did the work, but no kissing). I never felt pain.

I do feel like being intimate with my boyfriend (i didnt want to call us engaged yet, since our breakups over the cheating) sometimes, especially when I've drank a little. But ... that's not right :/

My boyfriend gets super upset when I tell him I'm not in the mood, or I tell him I dont feel anything when hes kissing me. I dont like having much chest touched (anymore) at all. He thinks I'm not attracted to him, and that's why I never comply, and that's why i feel pain when we try to have sex.

I dont think I'm unattracted to him. I love him as a person; he can be sweet, hes funny and smart, he is super helpful around the house, and we deal with each others' silliness in a way no one else would really get. I love him so, so much. But now even hes worried me.. maybe I'm not attracted to him sexually.

Has anyone been through anything similar? (Maybe minus the cheating)