Husband is pressuring me for number two

My husband and I had our first baby in April. It was not planned, but we were happy about it as soon as we found out. It wasn't good timing though. I had just finished university and was just about to start working and my husband does not have a well paid job, so we've been struggling a lot financially. Ever since I was cleared for sex again my husband has been talking about how he wants more children and how he wants them to be close and I've thought it was sweet and all but now it's at the point I'm not having sex with him anymore because I don't trust that he will actually use protection (due to medical issues this is the only form of birth control I can use). Sure I want more children, but not now. We need to be more financially stable first. He has a very high sex drive and our relationship is terrible now we don't have sex. I've been trying to talk to him so many times but he doesn't agree with me, he thinks money will "solve itself" and that we should try for more children while we can (he's 30, I'm 26). I have medical issues which should make it hard for me to get pregnant, so our baby was a total surprise and miracle. I get where he's coming from, but having it so hard financially is really hard on me and I feel I'm breaking apart. He's refusing couples therapy and says that "we might as well break up" if that's what I want. Please give me your advice. Everything was great and it feels stupid to break a relationship for something we both want, just at different times.