My boyfriend hates himself.

We are like year and a half together. I'm openly gay, but he is closeted which makes things sometimes complicated, but I love him too much and he loves me and I want to help him. He still can't accept his sexuality. For after every intimate monent he starts to feel BAD. He says things like we shouldn't have done this and why I didn't stop him. I tried to stop everything, because I don't care much about sex, I just want to be with him, but he says that everything is going to be all right this time and every time I fall for this trap and afterwards he starts to feel horrible... Which makes me also feel horrible, I start to feel that I'm developing a trauma about this. I am saying that the closet has a "pressure" on him, and if he would come out, he will feel a relief, but he is resisting, trying to find 1001 reasons why he shouldn't come out. He says that the main reason od him being in closet is his mom, she has diabetes and some other health problems, she expects grandchildren also she is conservative about sexuality and he is afraid of letting her down (stupid reason if you ask me) and he is scared that something horrible can happen to her if he will come out(like heart attack) in my opinion nothing horrible will happen, but he won't listen. I suggested him to go together to some lgbt meeting, he always refuses. Right now I am out of ideas and don't know how to help him. Reddit, please help...