@Gettingbysomehow you sound so overwhelmed. It must be really hard for you as you are ,and have been, dealing with so much. Too much!
Having had periods of being incapacitated and on crutches I know how bloody exhausting and awkward general living can be.
From the tone of your messages I'm sensing that you may be at the 'straw that broke the camels back' point. Where something like this (which is shitty and irritating) just becomes a huge issue that makes you sit and just cry - where usually you would cope and just deal with it.
Is there any way that you can get some temporary local help ? Can you further delay going back to work so that you can build up mental and physical strength a bit more ?
My personal experience is that if you rush going back to work you are more likely to boomerang back to sick leave.
Have a cuppa, sit and a think. Is there anyone you can ask for help? Asking for help is hard, especially when you don't usually ask! But people like to help (As long as you don't take this piss).
Sometimes women are our own worst enemy. I'm betting that you are proving hard - to yourself and ex - that you can cope, that you are strong , that you can do this all on your own. That you're superwoman. Maybe you are, but give yourself a break.
I may be projecting/ seeing things that aren't there. If I am, apologies. But having been in that place I know how hard it was to recognise and do the things that would help in the long term.
Take care. X