I echo Puppy. You are in the first stage which is SHOCK. During this phase you do not make any important decisions without getting 3rd party help. Find a good attorney and start protecting yourself. These threats are empty. Your WAH has no clue what he is getting into. His attorney on the other hand does this for a living and deals w this everyday. They make money dragging this process out.
If you don't agree to anything then it will take at least 2 years depending on where you live. The first thing a judge will do is have you both figure out a custody/co-parenting agreement. The court is really only concerned about the kids for the first part.
So talk to an attorney you like and trust. Dont move out. DOnt believe anything your WAH says and only half of what he does.
Just tell him that you are sorry this is happening and that he feels that way, BUT you dont believe in tearing apart your family and will do what you have to do to protect it. Then tell him to do what he NEEDS to do.
Use this time to figure out what you need to work on. If you feel you have an anger problem then get help. Use this time to work on you.
As mentioned above, no matter what you can't stop your H from doing what he wants but you can protect yourself and not rollover.
This is a long process and it can go as fast or as slow as you want.