There are a lot of things that YOU will have to work through for yourself during this time.
In the event that your M makes it to the other side, YOU need to be as healed and healthy and whole of a person as you can because even at that point, your H, will still be pretty broken.
He has done some things, things that most people would be ashamed of, or at least would want to keep very private.
You have to find a way to deal with them. To either decide if you can honestly and truly forgive him, which means never mentioning them again, or if they are going to be deal breakers if the you two reconcile. Because those things, if they are things that will be brought up, will hurt you both down the road.
I know this sounds like an impossible task, and to be honest, when I read your intro, I was not sure if I would be able to be supportive. Because I don’t know if I would have the intestinal fortitude to forgive and to not hold onto judgement in the same situation.
I am very glad that you have been to the doctor, and at this point, I would suggest, no physical contact (they do sometimes attempt it), simply to ensure that you don’t end up with any unwanted surprises. If your M reconciles, that is something you can deal with (the medical aspect of it) then.
IMO, you really need to not worry about your H at all right now, and really try to take some time to decide if you CAN do this. Not if you want to or not, in your case, at this point, I almost think it is not important right now. You can figure out if you want to or not down the road.
CAN YOU, forgive all of the infidelities, the immoral acts, the lies? CAN YOU?
I am sorry that I am the big party pooper here, but if I was in your shoes, this is where I would have to start.
"Acceptance doesn't mean resignation. It means understanding that something is what it is and there's got to be a way through it."--Michael J. Fox