I guess technically you were 'controlling the finances' because you were the one earning the money, but realistically, what else could you possibly have done, as a responsible adult and parent?
I think I'd sidestep that label altogether as far as you can: certainly don't attempt to defend your conduct to him. The less direct contact the better, I'd say.
I think with 50:50 child split, neither of you would be expected to fund the other, but I'm no expert.
His gravy train has hit the buffers so he'll say anything to anyone. Doesn't mean you have to listen. I'm glad you got the house tied up so he can't easily take you to the cleaners! Also, the house is the children's home, so it's highly unlikely you'll be forced to sell it from under them. You might have to buy out his share, which no doubt means 50% in his mind but I'd be inclined to start from 10%. You probably will have to pay him something to go away, I'm afraid.
In the UK (where I see you're not) the starting point for dividing assets is 50:50 but not, I think, for such a short marriage. I would imagine you have loads of evidence for how you had to spend to compensate for his shortcomings as provider and parent!
But the other line to pursue is the emotional abuse, for sure.
The children are the most important people in all this and their views about where they want to live and how they want to divide their time will be listened to if they are old enough to express them. Do you think his substance abuse makes it doubtful he will be awarded unsupervised contact?
I'm so glad you're beginning to be free; good luck with the rest of the process. I trust you have a good lawyer!