Welcome back!
Yea ... its very scarry... but your not alone.
If your going to Al-anon then you knew on some level that this would happen if he did not recover, it gets progressively worse and it sounds like you have been keeping him afloat for along time... he does not have to recover cuz you are there for him.
BUT Im the worse about staying in something long after I should have gone... in fact I would probably still be with my ex-abf if he had not decided it was over when he did... I was pretty sick, not that Im All better now but Im better.
I thank God everyday now though that he removed me from that... it was Way scarry at first, but you can do it... and the peace of having control over my life ... at least not having to deal with someone soooo unbalanced... is truely amazing.
Keep coming back and posting ... your not alone