You should have stopped giving him money to go pub and used that money to pay off your debt. You could have sorted quite a lot of it by now.
Nothing will change unless at the very minimum you stop giving him this money.
Let him kick off, just say you have not got the money to give him.
Pay your debts and improve your credit rating.
Then when you are financially in a better off position and no debt, look into moving out. He treats you like this because in part you allow out. I know as I've been there. Nothing will change until you change.
You can't change him, he has chosen to be this with you. He doesn't care if you have no money for milk. He is also depriving his own child, what a crap partner and father.
So let him pay the house bills and use this time to pay off the debts and get yourself sorted. Let him kick off. But keep that money for your debts.
Then look at your relationship.
Don't do what some others have said and leave as UC is a shit storm, at least pay down debt first and maybe even get some savings behind you first.
Long term your relationship is not working so you will need to leave.