It sounds like it’s early days if you haven’t see a solicitor yet.
My STBXH was similar with his demands, telling me what he would accept and what he wouldn’t accept. He had also been emotionally abusive.
Encourage him to get a solicitor if you can. My husbands demands were modified by presumably his solicitor explaining the law and what was reasonable.
Having you own solicitor is absolute necessary. Mine sees through his bullshit and de-escalates my panic everytime.
My STBXH is trying every trick in the book, and has just binned his second solicitor, and is going it alone again. He gets annoyed when I ask him to deal direct with my solicitor and not me.
Just a word of warning. Whatever behaviour has made you want to leave him, will ramp up in these early stages.
To you the divorce is about getting to live your life in peace, for him it shows the world he’s a failure and he will hate that.
Learn to grey rock and don’t reply to every angry things he says or write. Let him vent his rage into a void.
It will be hard to hear this, but who does Xmas this year is not what you should be spending your energy on at the moment. Sorry.
Oh, and try to keep all contact in writing (text and email), and write down any conversations you have, or things your children say, straight away.