I agree file for legal separation - I think in NJ it may take 18 months for a divorce to go thru.
After you are separated for awhile you may decided that you don't want to be with him, at least this will give you some time alone to sort out your feelings and see if he will get help.
I would talk to your kids before he does, don't go into details. If they have seen the fighting they may it also might be some stress off of them also.
What is the circle of abuse?