There's no way to know, reliably, honestly.
How long until your sanity gives out?
You are free to leave, honestly. There is no moral logic to staying with someone who VOLUNTARILY is destroying themself. He has had medical attention, been sober, and still chooses to return to self-destruction.
You don't have to go down the tubes with him, you are free to separate your life from this madness and pursue your own health - mental, physical, emotional.
Honest.
Just give yourself permission, and free yourself from your misplaced guilt. The guilt is not yours to own, because these are consequences of HIS choices, HIS free will. You have no control over that, so do not own the consequences or the guilt of the results.
Welcome! We are here for you as you go through your process to make YOURSELF healthier!!
CLMI