OP - what will it take for you to see your situation clearly? Please read up on financial abuse because there are so many PP that are spot on.
He is isolating you, keeping you financially vulnerable and even has you explaining away his abuse with pregnancy hormones and his ex who fleeced him. It's also very clever to split expenditure in a way that is "fair", i.e. you cover bills and paid for the wedding so perhaps the figures evened out, but without you gaining any long-term, financial security. This is very deliberate on his part.
Surely if he was "fleeced" once, written agreements would be ideal to protect his assets as well as to define your investment. You're a live in cleaner-cum-incubator and to top it off, you subsidise his bills. You say he's a great dad and asks for more time when he sees his kids, but why didn't he get 50/50 custody in the first place? Is it possible that his ex felt trapped and aware of the insiduous abuse so wanted to limit his contact with the kids? I speculate but surely you only have his word for how that relationship ended.
He planned a baby with you, paid for IVF, but now that you're pregnant he wants you to cover 100% of the costs, with no finacnial stability in "his" home (despite it being a marital and soon family home), no financial support to cover reduced working hours (which will almost certainly be the case) and to carry on working to boot. Please, please, please get out.
Go to your family, tell them your honest situation WRT contributions/split of assets, and let them help you.