Welcome to SR, indirectvictim.
So sorry about your broken heart...recently I split up with my fiancee because he chose the booze/pills over me. We dated for nearly 4 years, so please consider yourself lucky that you put your foot down early on in the relationship. I spent 3 years of back and forth before I learned what I wanted my boundary to be (no drinking and working a program in AA) and actually enforced it.
Read more of the stories here...I think you will come to realize that you really are fortunate for not dragging out the relationship any longer. Take care of yourself - you deserve better!
Karin