Fiancé says conflicting things

I’m really struggling with my relationship with my fiancé right now. We’ve had lots of conflict over the last year. Lots of it centering around my issues with his overdrinking. He perceives that I’ve criticized him to the point of him changing “everything” about himself. He has said recently (while angry) that he’s miserable all the time and hates me. Then when he’s in a different emotional state, he will tell me he loves me, I’m his everything, he can’t wait to move to a new city with me (planned for this fall), etc. I don’t know what to think or do. I just get stuck in confusion. I don’t want to leave him. I think things can be good. But maybe I’m lying to myself.