My qualifier did eventually get sober and, as far as I know, has been so for upward of 20 years. He has children and a career and a relatively productive life.
I've found a medication that works for my depression and have done some interesting things in my life: learned a second language, traveled, and developed relationships with my nieces and nephews.
He did tell me, years after I left him, that I did the right thing. If I wasn't so codependent, I would probably value saving my own life more. However I tend to value a belief that I contributed to his recovery by leaving. My success was doing the right thing. My fantasy-romance that was going to magically save me from my own issues was a complete flop.
"Hope" is a concept that most of us here have mixed feelings about. If you can at all do it, start working on a plan: boundaries, detachment, support, and ways to go no-contact if you need to.