Ss06, I honestly and truly believe there are a LOT of positives in your situation, despite how it seems. But you have to remember that it always looks different to an outsider than an insider. I do think your H needs a lot more time, but I also believe in this old Shakespeare (I think) saying:
"Me thinks he doth protest too much" (or something like that)
He repeats these feelings because the more you say something out loud, the more it must be true. That doesn't mean it is. But he is probably trying to convince himself of that as much as you, because then he can't feel guilty or like he has done the wrong thing, etc.
Unfortunately for you, you are going to have to keep chugging away, slowly but surely. And it might take a long time. But you have a few things on your side: a great co-parenting relationship, no OW that we know of(??) and the fact that he seems to enjoy being around you and your D.
Keep these things in mind and focus on what you CAN do, not what you can't. You CAN present a PMA every time you see him. You CAN look good. You CAN validate his feelings at every turn. You CAN make every interaction he has with you and your D a positive one. You CAN be a better person. You CAN enforce the changes you have made, whether he acknowledges them or not.
As for making yourself better, keep all the above things in mind, but also find out what lifts your mood and do those things all the time: movies, walks, snacks, takeout, exercise, cleaning, manicures, facials, time with friends, reading, playing with your D, etc.
And also keep in mind natural mood lifters like laughing, exercise, etc.
