Help!

So my boyfriend and I have been together for almost a year this November. In the beginning of our relationship we had sex frequently. And now not at all. We haven’t had sex since JANUARY. And every time I ask him about it he says that it has nothing to do with me and he is just self conscious because he thinks he is bad at it. He also said that he is just way to stressed out about work. Like what? It’s been way to long. Ever since I said something he now brings it up saying like “we can have sex tomorrow I promise” the day after I said something to him he tried and no matter how much I wanted to I stopped him because I feel like he was only doing it because I said something.

Any suggestions?