Glad to hear you are doing well! Sorry to hear about the in-and-out from your H, but that's to be expected. He came back too soon and did not do any of the work he needs to do. I'd say chances are good he'll be back again so here are some suggestions:
1. DO NOT let him just move back in on a moment's notice. He needs to learn you don't have a revolving door that he can use whenever. He also needs to learn that he could lose you.
2. Prepare a list of requirements before he can move back in. The minimum on that list should be IC and MC sessions BEFORE he moves back. Another item should be TOTAL TRANSPARENCY meaning you can look at his phone whenever you want without warning. If he cries about it then explain he's given up his right to be trusted and he has to rebuild that trust through transparency.
3. Insist that he write a letter, email or text to OW ending things and telling her he is committed to you, and make him send it while you are watching.
If he REALLY wants to come back he will be willing to do all of this and more. Like you said there needs to be remorse on his part and he is not there yet, he has to hit bottom and he hasn't. Hitting bottom usually doesn't happen until after they realize they've probably lost their LBS for good.
