First, you are likely to see at least some of the money and if you do it correctly, he will pay the legal fees. Make sure that is on your wish list to discuss with the L.
YOU cannot make him feel anything about you. He controls his own feelings. Right now, I don't see a man who hates you. I see a man who feels nothing. He doesn't concern himself with how his actions/words will make you feel. He constantly throws OW and her offspring in your face. He takes every turn he can to hurt you even when(you might even say especially when) he knows it will hurt you.
Just do what you need to do. You can't make him do anything more than he's already doing. You keep stopping yourself from protecting yourself and DS because you fear loss of connection with him. For now, it's lost. Hanging on to the pain is not helping you or DS.
By the way, you are a responsible mother. Regardless of how you feel about OW, you need to have a plan to pick up DS from _____ in the event of her hospitalization. Tell your H to pick someone, maybe BIL?, and have that person call you to pick up DS if it happens while he is visiting.
