used for sex... I think

I think in my last relationship I was used for sex. We were each other's firsts and every time he came mine or I went his, he had had sex with me, we used to stop right after he finished and he didn't really ever ask me if I'd finished, if he said do you want to continue, id say yeah then he'd try for A few minutes then stop and say he "can't". We rarely did foreplay, and I feel like the relationship was just based on sex. If we hadn't had sex in a day, he would have sex with me just before one of us left to go home. I felt like I couldn't say no to sex even though sometimes i didn't want to have sex, I just did to make him happy and I knew he would most likely be in a "bad mood" with me if I did say no. 
I get so upset about this now as I look back on it. I've recently seen how my friend is treated with another boy who she isn't dating and he seems to treat her with much more respect than my ex ever did. 
I don't think he intentionally used me for sex, but i know if I ever told him now that he used me, he would get really mad at me, call me deluded etc. 
Sorry for the long post, I'm just really upset.