The way you've been handling everything has been great. In fact, since you said that your H is a celebrity and he's been posting pix of him and his OW while you're with the kids, he's got some nerve to say how hurt HE is. I think to a certain degree he craves a certain amount of attention and for once you're not giving it to him.
What I read in his messages to you was all blameshifting. "Oh woe is me, my W and family are rejecting me. That's why I HAD to move somewhere else, blah blah blah". He hasn't taken any responsibility for the things he did. Almost all WAS's do this. I understand if he felt like you were distant with him in the past, etc., but the LAST thing a MARRIED person does is to find another person.
Unless your H is in high school, that's not the way you deal with things.
You're doing very well. Keep your concentration on your kids. And to be honest, it seems like he's monitoring your FB posts indirectly, so I would suggest you post every happy pic you have with your kids and out on your own. Show him what he's missing. Keep up the great work!
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.