advice please.

So I'm currently 13 weeks with my second baby and have a 3 year old daughter. My husband is not the father of My daughter but is of the baby. We have been fighting a lot lately. Most recent is me needing help with buying scrubs for work because I started a new job. I asked him and he said as long as money is back in his account when I get my first check. I told him I refuse to ask him for help because I always have to pay him back even though we are married. I think that's a little fucked up. secondly I told him if things don't work out I wouldn't ask him for help because I shouldn't have to pay him back fnor buying things for his child. He told me that I might as well not put him on the birth certificate and that if we don't work out he is signing off his rights to the baby and walking away from it because it's not fair to the child. I'm just curious as to what to do in this situation.