STOP! Go to a solicitor, it doesnt make ANY difference who divorces who. You have the children and are in the marital home, you're going nowhere. This bully is bluffing because he is panicing - he is losing the control and scum like that cant handle that.
Get an interdict to stop him coming near you, change the locks and tell the police whats going on, it will help if you have to phone them.
He can refuse to sign the papers all he likes, the VERY longest it will take then is two years then it will go through whether he contests it or not.
Get to a solicitor now and get legally seperated in case he runs up any debts, from the date of the legal seperation you wont be held jointly responsible.
Good luck hon, you have done the hardest bit, its just patience and courage now and it will end one day x