My Boyfriend has issues in the bedroom, what should i do?

My boyfriend is currently on anti-depressants for anxiety. This is meaning that he cannot finish. This is a huge issue for me because i feel like it's my fault that i can't make him happy. I have asked him to go to the doctors to find out if they can help at all and offered to go with him for support but he just outright refused. What should i do? I'm a sexual person and don't like the fact that i feel awkward doing things with him when i know there wont be a happy ending. We recently started arguing and i feel like im at the end, if he wont try and change things to help me feel secure (and obviously to help himself) I don't know how much more i can take :(