Abbey, for me, knowing took away the chance to win him back in some ways. Once I knew, he bolted to avoid the confrontations and feelings of guilt. I know this [censored], but keep doing what you are doing with DB'ing. I've seen amazing results in our interactions (whether we reconcile or not, he's treating me and our kids with respect a lot more than he was in the last year) and it's helped me let go of a lot of anger and hurt. I went from making myself be upbeat to it coming more naturally to me.
Some tips to help you through the "faking it" period- def make small concrete goals for your interactions with him and overall. I started reading/looking for news items for casual discussions. I look at things that interest me and share them sometimes. I'm spending more time with friends and family. (Your mom thinks you're awesome...she knows you better than anyone else in the world, so own how awesome you are). I wrote out a "bucket list" of things I wanr to do and things I have done and things I want, but don't think I can do (maybe I'll find a way to get them back on the to do side). I've started crossing things off and it feels great. Even little things, like trying new foods or helping others, can give you a boost.
Smile, it's sexy. (Thanks to Coach Chuck). Take some time for you - go tan, get hair or nails done, etc. Buy new jeans that make your butt look great. Simplify life - start dumping clutter and it is freeing. Be positive - did you hate the movie, but discover a new fav song? Get up, get out and do things. The hard thing will be getting him to do things with you vs using your absence to justify going to OW. More experienced people here can help you with that.
He's going to cheat on you with her until he realizes that he's cheating himself by missing out on his amazing wife. Find your inner glow, love yourself, and if he doesn't come back/leave her, you'll have a line of loving friends waiting for your time.
Faith is, at one and the same time, absolutely necessary and altogether impossible. --Stanislaw Lem