I've been in your shoes. I was the eternal optimist, hoping that things would change.
I married him. We had a baby. He finally got sober. Then after less than a year of sobriety, he is back to active alcoholism. My AH was the same, hiding vodka bottles everywhere. Sidebar: I cleaned out our community condo closet (was a member of the board) before we moved and found LOADS of vodka bottles in there. I mean, the place where ANYONE can go in? Where the gardener keeps the tools? Please.
Anyway, I am in the process of starting a new life. It's scary but I can only keep trusting that things will get better. Time has taught me with my AH that while we had one really good stretch, everything else has been pretty terrible.
I know no one can leave until they are ready (I'm a perfect case here) but I'd encourage you to just consider how different your life would be if you weren't on eggshells all the time, if things were just predictable. You have choices.
At my AH's last intervention, the interventionist (sp?) told me that eventually I was going to have to choose what I wanted, rather than just making "passive choices" based on AH doing this or that or the other. I say it again--you have choices. Think about what you need and that should come first.
And please, please don't marry the guy. As I am learning quickly, divorce is very expensive!