I agree with Mark. I have a similar situation and was lucky enough that by the time I decided to end it I was in the middle of my sixth and seventh step. I apologized to him for involving him in my problems with alcohol when I corresponded to break it off. Neither my sponsor nor I believe I have to make any additional amends to him.
I know in my heart that any thoughts I might have about contacting him again would be coming from the wrong place. Not to say that's what you would be doing-- only you know that-- but it's a place where I think you really do have to dig very deeply into your sixth step (willingness to let go) and be brutally honest with yourself about your motives and so forth.