I carry the weight of his revolting behaviour with me every day
Another one whos heart sank when I read that.
OP You want this to go away, God knows I know how that feels. You want to wake up, it not to have happened and for life to continue as normal. You are doing what I and countless others have done, and tried to brush it away. It was a mistake/he was drunk/it only happened twice/he was trying to make sure it didnt happen again/he is telling me the truth......
Then you spend a couple of weeks having the best sex ever, better than you did when you first got together and you feel close than ever before.
Then you crash. It all comes out, your hurt, your betrayal, the sheer disbelief that he could do this to you. That is when the healing starts, its when you think about it in terms of "So what if he was drunk, it was a mistake, it only happened twice....HE STILL DID IT" You start to think "Well I have been drunk, but I never shagged anyone else!" You remember times when it would have been quite easy to have sex with someone else, but you didnt because that ring on your finger meant more to you than anything else.
It will come, and it needs to come, because otherwise it will stay inside you while you try to keep the facade going and it will rot you from the inside out.
Go with the flow. Whatever emotions you feel, let them happen and deal with them in whatever way feels right at the time. Eventually you will come to an even keel and you will be able to think straight (ish!) you just need to weather the storm until that happens. I am thinking of you.