Was I sexually assaulted? It's all very confusing..

So I have an ex bf who was very manipulative and mean. But when I had feelings for him I would go over to his house often to chill. Unfortunately he only liked me for sexual things or kissing. When we agreed to stay friends he would still kiss me on the mouth in privite or even in public even when we weren't even together (as if he was trying to claim me or something). Whenever I would be alone in his room he wanted to do sexual things and didn't take no for an answer. I feel like it's partly my fault because I have into his peer pressure. I don't want to say what he did because it makes me feel embarrassed and used. Another thing he did was when we agreed that we weren't going to do something before hand (because I wasn't comfortable with it), during the act he would do it anyway. Without my permission. I feel like it's partly my fault because I said yes and gave in... I know better now but I was just wondering