I am sorry wtbh, he truly is disgusting to terrorize his own children this way. Why haven't you used a GAL before, just out of curiosity? (I know your state is complicated & you had to tread carefully through your options.)
I also agree with the others that he's going to push harder, expecting to wear you down. He has NO point of reference for you holding your boundaries so ALL he knows is to keep pushing. He likely isn't even considering what may happen as a result.
IMO, with enough rope he WILL hang himself, but you have to be able to stay safe & sane until that time comes. Talking it out here is great. How about journaling it - even if it's just filling pages with fragmented verbal vomit that you immediately throw away, it can be cathartic to get those thoughts out.
You ARE getting stronger, I can "see" it even if you can't (yet). ((((((HUGS)))))