Get out of that relationship now.
Goodness, this made me shake my head in disbelief. Mostly for myself, because I've been there, done that.
I spent 7 years with someone who was tight as hell and I couldn't see it for a long time. Most of those 7 years we lived together. Sadly, I needed a very shocking wake up call - when I got depressed and ended up being unable to work and bring money, that man was annoyed with the fact that he had to pay most of our living expenses for a while. For me, it's a no brainer in a normal couple's household, if one partner is seriously sick, the other will take care of them and help them regain their health. It would have been a no brainer if it was the other way round and I had to work for both. But no, not for that guy. He basically didn't want to comprehend that I was sick and broke, which made my depression and feelings of worthlessness even worse and hindered my healing. Even after we broke up, he kept contacting me asking to give him back my share of this and that. Nowadays I know that him being a tight materialistic idiot contributed to me becoming depressed and pressured in the first place.
The only good things in the whole relationship was that it was a lesson and I left the relationship still young enough to find a loving, mature man and start a family where everyone is truly supporting each other through thick and thin.
What you mentioned about him paying for his daughter doesn't show any generous nature at all. It shows fulfilling of a duty. You can do so much better than him and don't need this sort of a burden. You have yourself and a small child to think about, not about counting every penny you owe to your personal money management police office who will breath down your neck every day of your life.