OP, I think it sounds as if your relationship with your husband has you stuck in parent mode and him in child mode, and you're weary of it.
there are two ways of getting out of that:
- ending the relationship (though you will still be co-parents so it's not final)
- changing the dynamic.
There is a pattern here of him responding like an emotional child to an authoritative parent (tantrumming and not going on holiday, and then relenting and wanting to come, is just like a child responding antrily to a boundary, running away to a bedroom and missing a meal or an outing, and crying and joining later). While it's obvious to us all that it would be better if he didn't behave like an emotional child, the clever part is how you can set him free from this by behaving less like an authoritative parent.
The tricky bit is that you need to behave with authority where the things at stake really matter and where you seem to be the only personal capable of making rational decisions (eg around child safety). So you just have to leave all that where it is.
Can you just let the rest go?
Whether you actually separate in the end or not, I wouldn't issue an ultimatum, because you need to free yourself from this tiresome role as much as you need to be freed from the exhaustion of putting up with the part that he plays.
Let him go over Christmas. Give him a present when he comes back. Have a good time, see friends and family, don't do anything strongly reactive (either hostile to him, or weirdly extravagantly celebrating his absence). You can be honest in private about how hurt you are that he has done this without it triggering a huge reaction of admonishment and punishment that he will then have to re-react to.
(I notice he doesn't like you working - of course he doesn't - mummies don't work (in his child-head). Again - of course, he doesn't get to decide whether you work or not - but somehow instead of him framing this as mummy angrily withdrawing care, he needs to see this as an adult getting on with life and co-parenting in a modern way - if he can't then maybe you don't belong together)
If you can re-make the dynamic and improve the relationship, then good.
If you can't, and you split, then better you leave as an adult deciding to co-parent with another adult outwith a marriage, then as one person angrily withdrawing from another because needs aren't being met, then boomeranging back filled with grief and loss, and then more punishment happening, and ... and... and