Wow, if you only knew how your post reflects my thoughts and life...wow...
Please don't blame yourself for any of this..in my son's 'sober' moments we have talked about this, and he's emphatically looked in my eyes (not a usual occurance these days) and assured me that no matter what I would have said or done, it wouldn't have changed a thing.
If you believe in a 'Higher Power' now is the time to put this in his hands, I'm serious, I've been there and He has never let me down....