Gwyn, you have asked several times if we all think you should go home. Only you and your H can decide this. He says he doesn't think you are ready and he may not be ready either. I would suggest having your MC mediate a conversation about this too.
As far as his request to not talk about the A. I think it is really important to consider the request. He knows he made a mistake and he doesn't want to keep being reminded about it. He wants to forget it and move on. I believe going back and rehashing this with him over and over is not healthy for either of you. It will get you nothing but hurt and angry all over again.
My H didn't want to talk either. I didn't want to know any details about his A, only why he did it. He did it because our M was bad, he felt bad, and he was looking for comfort. That really was all I needed to know. He didn't do it because he didn't love me, he did it cuz he was feeling bad and was looking for something to make him feel better.
So I left it at that and we never talked about it. He apologized to me the first day I found out about it, but he kept seeing her. He finally broke it off with her but he never apologized to me again. In his mind, he just wanted to forget it and move on.
To me, I couldn't see any point is going over it again. It would be painful to discuss and some things I just didn't want to know, and he didn't want to talk about. We both wanted it to go away and by not obsessing about it, it eventually did go away. We wanted to make that fresh start and let the past be the past. Can't change it.
We both know what happened, but we really don't need to talk about it. We started over in a new M. The A was in our old M.
I know it's hard, Gwyn. There are things you want that he doesn't want to or can't give you. It is hard on him too.
So try to let it go and move on. That is what you both want and if you plan to go back home and try to start over, you have to leave this in the past.