Jesus Christ on the London Undergound with an Oyster Card and a Ukele.
Firstly .tyresarerubber , in what why is that helpful? WWYHD then smartarse?
Brave putting all that online and not running to the hills sooner.
I take it by posting you want some ideas on dealing with the sh1tstorm so I shall compartmentalise
Wife, leave . Im sorry no point in carrying on . You kids will not benefit from living in such a broken household. She can rent a flat with SD.
House . Rent it out, tell the stbxw to do one.
Step Daughter . Go non contact . Ignore the toxic cow till she gets the help she needs.
Kids. Get a full time nanny / au pair to look after YOU , your Dad and kids. A well organised person should be able to do school runs , cooking , washing and cleaning . Polish / Czech would be good . They work hard and shouldnt be too expensive. Try not to fall for them though, best to get a hockenmoose maybe.