Intimacy issues? ruining relationship?

[mia]

My boyfriend always says I have them. He used to be fat and now he's lost a lot of weight and other women are noticing him and I guess now im starting to feel insecure. Like im not pretty enough. I don't like to be on top during intercourse I don't like him to stare at me today during our intercourse I just stopped! Because I was on top and he was looking up at me and I just didn't want to anymore. I know im ruining us. We're probably going to break up im pushing him passed all his limits. He hasn't talked to me since then and im just sitting here like omg what have I done? I really do love him... but if we're done its going to be my fault. Should I tell him that im insecure. Will it help him understand now. Bottom line is I don't want to break up and I realize now that the way I've been treating him is not okay