Your focus is on the wrong thing. I mean this gently, but you need to leave.
From your children's perspective, you've let them down massively. You, their mother have chosen to prioritise a man who hates them over your relationship with them.
He kicked off at your dd who was 12, ruined your ds's birthday and beat you up and you dismiss that as a break down but it wasn't was it? It was his abusive self coming out to test what you'd put up with and you showed him you'll take his side.
As far as the money goes, you cannot afford to be self employed, making a small amount of money and having this man pay your bills.
You're trapped with him and as he's shown you, he can leave you penniless at any time. And he will.
There are so many reasons for you to leave him - the verbal and emotional abuse of your dc, his physical abuse of you, his financial abuse of you, that he's an awful man and a bully. Pick any of these, get a job and get out.
And apologise to your children for inflicting this man on them.