Hey Pam. It sounds like a very understandable tough situation. If you haven't found them yet in your reading, I'd recommend reviewing Sandi's Rules. Sandi is, to me at least, a legendary poster in this forum. She's not been active for some time and, hopefully, just stepped away from the board. However, her list of rules was a lifesaver when I was at the point that you seem to be at. I made myself memorize those rules like I was in elementary school and practiced them daily. With an MLCer, it can take a long time and much patience but if there is a chance they'll turn around, Sandi's rules can be a very helpful complement to MWDs DBing. And, you will backslide here and there or make errors. Focus on you for now using (as DNJ said) the gift of time you have. Your self-care and well-being are of most importance with your kids following very closely. Tough to be fully there for them when you're not at your best.
Talking with a lawyer is just that: talking. Don't share with H. I spoke with 4-5 and got better at asking 3, 4, and 5 more sophisticated questions after I'd gotten my typically one hour free consultation with each attorney. Hit your local library to review a copy of Divorce in (INSERT YOUR STATE NAME) with Children. It gave me a great sense of what I'd face if that route became a reality I had to face or choose.
Boundaries are only as good as your enforcement of them. H may not like them, but you likely put them together for good reasons and your best interest.
Also, I'd not share all those feelings with H. Get an IC if possible. Air those feelings out in this forum for us instead, at least for now. Unfortunately, sharing with H right now can have unpredictable results. He may feel worse for hearing how you feel. He may take odd pleasure in it. Who knows! Do more of what is working for YOU and less of what is not. Read through others' situations out here to see what takeaways you may be able to apply to your situation. In my experience, you have to pick 2-3 things to really try from MWDs recommendations and then evaluate if they're having a positive impact for YOU. What 2-3 things have may you already have tried?