Oh Dowser bless you, Christmas ffs. What a horrible time for him to do that Never a good time I know, but of all the days.
.AleC, cry it all out, you are not super woman, dear God, I used to howl like a wounded dog when the kids weren't there. I'm betting the other posters on here can relate to that, and 'crying silently' at night when the kids are sleeping because you don't want to wake them and upset them.
Just because he is running around like the Duracell bunny on acid doesn't mean you have to. You don't have to go at the same speed as him. Set your own pace. Don't be bulldozed by him.
The thing is, you can't catch him up, because in his head he's months ahead of the game.
Leave him to his own agenda.
What I would do is only have contact with him about the kids, preferably by text. Keep it to the point, and don't do small talk.
If (when) he pushes about finances, say you are not going to discuss it, he'll be hearing from your solicitor. He will not like this. Tough. The last week hasn't been a bed of roses for you, has it? Dry your eyes my lovely and practice saying it in the mirror. You need to say this to him, probably a few times,, and nothing more.
Are you scared that if you detach he will play hard ball? He'll do that anyway when he gets his lovely little deal thrown back in his face by your SHL.
I know you love him, but you can and will get through this, don't make it harder than it all ready is by listening to any more of his crap.
Set your own agenda. Set your own pace.
Hugs