OP can you do something for me and look up Dr Ramani on YouTube, you will gain so much knowledge, and may even get a few pointers on how to deal with someone like him. Blimey had I known of this woman and her vlogs I would have saved myself and my child some serious years of control and abuse.
Your ex knows fully what he is doing, and so what you need to do is be a step ahead, level headed, and calm. He is going to paint you out to be the bad guy, and the reason is YOU LEFT. How dare you leave him. To him you will always he HIS, and whatever you say, do, plead, beg, revert to being a bitch or whatever side you attempt to fight him with, will never work.
What you must not do is give him ANY insight into your day to day, if its not about the kids, house, bill, he has no access to you. Non. He is not your master, but a mere boy. You need to start seeing him for who he is showing you he is, an abuser, someone who treats the mother of his children, badly, he treats women in general badly.
If you are depending on him financially, and you are not in the UK. Get advise legally where you are. If you are in the UK, call womans aid, and take your phone to a phoneshop to see if he has bugged it with an app to spy on you. They always have to take things too far, and yes you will always be the villain in his story, while he attempts to paint himself to be the angel in the street, yet play the devil in the home. Armour yourself with knowledge and start with Dr Ramini