I think you're making the right decision in moving out - are you moving back home with your parents? How come he can't leave or maybe you don't want the apartment?? Believe me, if he's like this now, it will only get worse if you were to get married to him. There's no reason to have to tolerate him being like this.
I also agree with Shezbut and Bloom - don't let him convince you not to move by making false promises. Good for you (((salukigirl))).