Not sure what to do

Okay, so before we had our second child I made it clear to my fiancé that I wanted two more kids at least - which was a compromise since I wanted five or more originally. We agreed once he gets his next raise we can decide when works for us to have our third. Well our second is now four months and my fiancé keeps saying how he’s done. He no longer agrees that we’ll have three. And I just feel so upset. Like he lied to me. This is 100% a dealbreaker for me but I can’t imagine being with anyone else. I just don’t know what to do at this point. I don’t want my kids to grow up without their dad here but I don’t want to resent him which I know I will. What am I supposed to do here? My heart is breaking right now 😔