Right.
Let’s start with your STBEXH, clearly he’s a complete and utter wanker that should be thrown to the escaped animals (lions, tigers, cheetahs I believe) in Germany for a mid morning snack. But that’s enough energy wasted on him.
As for the important person here, YOU. Take the job.
I know you feel like you can’t cope with it right now, but you will. The thought of it is worse than the actual doing of it. You’ll do it because you need to do it.
All of this will be hard on the DC, BUT, it’s better to have one lot of upheaval than to get used to a ‘new normal’ (Daddy moving) and then another (Mummy working).
Call them and explain that you’re very sorry, but due to completely unforeseen circumstances you need to delay the start by a week. It’s not great, but you’re worth waiting for! You must be, the choose you!
Do NOT allow cockwomble to fuck the job up for you too.
There are plenty of nannies who will do full overnight weeks if you have to go away for work. Some will charge extra, some will negotiate extra leave in lieu.
STBXH will have to step up too, either in person or financially.
Get a VERY good Solicitor and get as much as you possibly can in the divorce because you will have the responsibility for the children.
I know how much it hurts, I know how much it turns your entire life upside down ((Hug)). I wish I’d had MN at the time! But the best thing you can do right now is get angry and use that energy to move forward fast. Try not to spend this early part dwelling on the past, what ifs etc. Just get moving practically, there will be time for reflection later.
I know it sounds harsh, but it really, really is for the best.