If you do nothing else keep a record of all texts & emails. Do not answer your phone & hang up if he does contact you. Do not reply with nasty comments as he might be keeping your replies. Keep a diary of visits and even non visits, phone calls and even communication from the new "lady" if she contacts you.

Get legal help now as they will be able to advise you of what you need to do. Once you have got a lawyer tell him all communication is to go through them.

If he is going to get nasty, nothing you do will change that. His true colours are starting to show so getting away from him is a good move.