TS, my only comment is = Assure thy self.
Assurance can't be the price of getting wed. It is just some paperwork with no life at all.
What's most important is you know that whatever may happen, you and your daughter/son can live without him.
Yes, I agree with your BF. If time doesn't show getting wed to be practical enough, then I think you have to understand and back off a bit. However, if you feel the urgency to get wed, then find another man who "Hopefully can be brave enough to get wed with you."