I'm so sorry that you ever were married to that guy

Remain strong. This is very, typical of such...at least now days the attorneys and judges are wise to them, not like 20 years ago
First off, it sounds as though the courts have already decided in your favor. What he is rebelling against is them, not you (though he thinks you are the fault for all his problems, I'm sure.)
What he is dealing with is no longer your problem, really. Do whatever you have to to stay safe. This includes stopping your thinking about him. Let the lawyer deal with him, and his attempts to reclaim you: have no discussion with the lawyer unless absolutely necessary. If the ex breaks the ruling, call the police...make a police report.
While it might appear to be nice to move away and hide, so he can't find you, they often do anyway and you would be in an area where they aren't privy to your legal issues immediately. Best to stay put, but do change your phone number and put it on unlisted unpublished. Tell the operator that you are being harassed and they will do this without charge.
If you have money to put up a camera or two at your home, then do so. Carry a camera in the car, in case you spot him following you or watching. BUT don't go looking for him. Knowing that you are prepared in case will help you not fear him so, and allow you to be about the business of redeveloping a life for you and your children.
If you aren't in counseling yourself, go. A good T will help you learn good self esteem and to dismiss unfounded fear. Depending upon the ages of your children, you might seek help for them, as living with any parent who has troubles (such as your ex must have displayed?) has an effect.
Don't worry that he seems to get away with his bad acts, he really doesn't. But that would take too much thought about him to discuss

Move on, and good wishes!