I know that you've done everything you can to be civil, etc., but in his mind right now, he doesn't see it that way. His thinking is very irrational. He see the situation as you are are holding all of the cards and pulling them in closer so that he can't get what he wants. What you are doing is absolutely the correct way of doing things, i.e., checking on how to go about this w/your lawyer, etc. Your h thinks that you should just do whatever he says and that's not how it works when separations/divorces/assets/families are in the picture.
You are following the right path...do not allow him to sway you from the path. You are doing what you need to do to protect yourself, your family and the assets for the future. He can't see beyond his little finger for the future, but you can because you are seeing clearly right now.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.