Child custody

Idk what group to put this in so I’m sorry in advance.

My ex out of nowhere decides he now wants custody of my daughter and unborn child, he claims he already has gotten half custody of his son from a different relationship and now if I don’t play nice with him he will take me to court.

He is abusive and violent, and he has even told me that his new girlfriend, who he has only been with for about 4 months, self abuses herself when she gets upset and neglects her own kids, which leaves him to care for and feed the kids as well. He and his girlfriend have been lying to get custody of the son, but I can’t prove that but I know there no way a judge would have approved that if he knew the truth. He even told me that they just found a place to live.

I have a few messages and a police and hospital report to prove the abuse but I’m scared its not enough. I don’t want any chance that he can have custody and put my kids in danger.

FYI English is not his first language so that’s why all the weird typos and grammar errors.

I feel like he’s too careful when he texts me and they aren’t enough to prove it. And I’m actually scared that if I do win he will come after me and try to kill me or send someone else to kill me, he has threatened me before. I don’t know what I should do. He’s never given me a dime for my daughter and hes never taken care of her at all. Idk why out of nowhere he just decided to take my kids