Welcome to the boards. It's a great place for support, venting, etc. And everyone here is on YOUR side!
Things to do immediately would be to just stop initiating any D-related actions. If H does, then come here and post and we'll see what we can do. But one step at a time, one day at a time.
The 'looking good' comment from your H must have been because you were doing a 180? Or did seeing you make him miss you and that's why he said that.
Continue with taking care of your looks, maybe change your haircolor, style of clothing, shoes, nail polish, etc. Your H is obviously noticing changes.
You haven't really said much about why your H was unhappy so as to seek another R, etc. Did he tell you why he was not content in the M?
You'll have to write down some 180 behaviors right away and also work on GAL (getting a life) immediately if you haven't already.
"Act as if": You are happy and content with yourself and life with or without H, specially around H.
Take care of yourself mentally and physically.
Reclaim the person you were when H fell in love with you!!
Give him something to come back to.
Read the 5 love languages book by Gary Chapman and take a stab at what H's love languages might be. Then start 'speaking' his language.
Tell us more about your situation.
Remember: An affair is a dysfunctional way of trying to save the marriage. I think Michele said this.