Thanks for your replies. It's good to know I'm not alone. While I know it was the right decision, I'm struggling with guilt over how I ended it. I just sent him his stuff and cut contact (after an argument over something else). But the real reason I left, of course, was the drinking.
Should I ever go back and make amends? I certainly don't feel strong enough now, I would likely drink over it...or maybe fall back into things with him...