Hello OP. I'm sorry your going through this. I'm in a very similar situation myself. My husband and I bought a house together before we were married, about three years ago. I wasn't put on the deed at the time as I was doing contract work. Since then we have had a daughter who is 20 months and we have got married.
We are buying a new house at the moment and I was worried my husband wouldn't want me on the deed as I am also not working and will stay at home with our daughter until she's three. However, because we're married it is sort of defacto that I am on the deed and would have caused issues with the mortgage if I hadn't been.
It's a tricky situation your in, and you have every right to be upset. Your sacrificing working to raise his child and you should be put on the deed to have financial security for you and your child if you were to break up. However, because your not married you don't have the protections you would have of you were married which puts you in a vulnerable situation.
If I were in this situation I would be very cross and to be honest I would probably threaten to leave. My argument would be that I am the mother of his child and if he doesn't want me on the deed then it's clear he's not committed to the relationship, so I'd be better off by myself claiming benefits and having child support, so I could support myself and not be reliant on someone who doesn't consider me to be a part of his family.
Honestly I would tell him I want to get married asap at a registry office so you can have the legal status and protections of a married couple because you are vulnerable as you are right now.
I don't know if that's helpful, all relationships are different but this would be a like in the sand for me.
Why doesn't he want you on the deed right? I would tell him he can have his big family house all to himself if thinks it's not yours anyway.