LNM just wanted to add my support. When we're going through terrible things, the 'copers' in life (of which you're clearly one!) tend to think "Oh it's OK, I can carry on, I need to carry on, I should be able to deal with this" whereas many many others in your situation would be a gibbering wreck by now. It takes strength to ask for and accept help and allow yourself to BE helped. You have plenty of strength, we know that. You need to use it to get yourself some time and space to recover from all of this.
If you read on here about someone who's been through what you've been through in the last month or so, you'd probably think "Oh my God how is she coping? I'd be a wailing puddle on the floor". But you have coped. And it's OK to say to GP / work "actually you know what? I can't do this any more without a bit of time to recharge. I need to take some time out to recover."
Even without everything you've been going through with Ex-H, your work situation sounds enough to have driven most people to the edge. Add that to a cheating ex-H who's now scaring you, assaulting you and who knows what else, I think it's about time you gave yourself permission to get all the help you need from your GP, get signed off indefinitely and do as everyone ^^ has said, write everything out in an email to your boss and their boss / HR etc detailing everything that's happened and the unreasonable demands being made on you.
Then take time to heal. And job hunt. And house hunt. Online, while wrapped up on the sofa with a blanket and a hot chocolate.
Huge hugs. We're all here. If you need help to make a plan / prioritise or anything like that just ask, we'll all do anything we can to help you create a happier, more secure future for you and your DDs xx