OP,
There are two threads that made me feel I had to sign up and comment on, this thread is one of them.
You are bloody amazing!
I can promise you this. The shock will be wearing off by now and you'll begin to feel tired, a little angry and just plain sick of it all...and want it over with. To go back how things were.
Don't.
Mourn for your loss, your relationship, the future you thought you had but please try not to forget that this is just a horrible messy way to a fresh start.
The angry moments are brilliant! Grab them and turn them into something productive, you'll move mountains in those days. Seriously, they really are great.
Don't hide your emotions, if you want to cry then do so. None of this ,need to stay strong crap, you'll make yourself ill.
On a practical level, please listen to this, learn from my experience with a shit show like this....
Keep a stock of paracetamol, Calpol and ibuprofen, toilet roll, uht milk and bread in the freezer AT ALL TIMES. You will be forever grateful they're there when you need them. Add pizza or brand, then that's two emergency meals when you're ill and have to feed the kids but there's no food in.
For further down the road:
Buy a drill and DIY book. YouTube is also very useful when fixing things and DIY. Don't be scared, just do it and you'll feel like you've discovered fire!
Ignore EVERYONE'S comments and gossip. It will blow over soon enough.
And I can't stress this enough...
No matter how you feel, how hopeless it all is, what people are saying.....
The kids will be fine. They will be absolutely fine. They will be happy and well adjusted, they will see your ex for what he is and his actions soon enough, they will make up their own minds about him without anyone elses input.
You'll make sure they are happy, fed, clothed and everything else.
There will be shit days, really shit days but great days too.
And you will come out of this a better, tougher, more determined, happier, healthier and more ambitious person.
Please believe me, eventually, you will see this as the best thing that's ever happened to you.
I know, I wanted to hit people when they said that to me too, but it is true.