Cold feet

Supposed to be married this year but today I told my fiance we should wait for marriage. He got really upset about this. I explained to him I would marry him but I just doubt sometimes if he'll stick around. He has a tendency to say that he'll move out, our relationship is over, he can't deal with this anymore, etc. during an argument/fight that are hurtful and gives me anxiety.

A week prior to our engagement party we had a fight, he said we should call it off, was about to pack his things and go to his parents. I pleaded with him not to and he stayed. He knows it's a problem but isn't willing to acknowledge he needs to do something about it. We are also expecting, I explained to him we need some more time because I'm truly afraid he'll just leave and I'll end up in a messy divorce. He was all silent about it but is there a chance it'll change for us.