Sara, I'm glad to hear you're D is OK. My youngest D has asthma and it's the scariest thing to have a child not be able to breathe.
Why are you still struggling? You need to give yourself time to heal. Lots of time. Everyone is different. It took me years to "let it go". I don't want to discourage you, but I never felt loved again, or maybe trusted it is a better way of saying it, after the 1st affair and that was 16 years ago. Maybe there was a reason for that because I'm walking that same path again.
As for WH,he's feeling tremendous guilt and knows he can't ever take back the betrayal. My H explained it that way to me the 1st time. He said he knew the pain he caused and knew he couldn't fix it. There's no way to guarantee it won't happen again. I decided then that I would there was nothing I could do if he chose to cheat again. I could spend my days miserable thinking endlessly about it (which I did in the beginning) or I could try to move past it and hopefully into a better marriage. I hope you can eventually move past it. I hope you can make a success of your marriage.
M:41 H:43 T:26yrs M:19 yrs S:15 D1:14 D2:9 Living together but separated