I'm with Lola, check to see if there's some kind of legal action you can take on support short of divorce. Your boundaries on OW are good but he is cake-eating big time on money. He can see OW with you as a backup plan, and he doesn't even have to pay for the backup plan.
Trust me, as a guy, we are attuned to mathematics. He needs to realize the financial impact of his actions on HIM not you.
Sad to say part of the reason I'm almost welcoming D papers rather than sitting in limboland is that a D would be better for me finacially than just waiting things out. I went the opposite route from your H and have been giving generous support.
Men are bottom-line driven.
Have a good day. I can't remember if you ever told me what grade and subjects you teach.
Me: 47, Ds 17-13, D final 6-11 http://tinyurl.com/yk4e2tz http://tiny.cc/thread2 http://tinyurl.com/ydtphqu http://tinyurl.com/thread4 http://tinyurl.com/3sm78k6 http://tinyurl.com/thread6