Hey Neecey,
I think we've all been as angry as you are now - at one time or another. Wow, do I understand where you're at.
There wasn't much that helped me when my anger was raging, except to wear myself out physically and mentally with other, useful things. Work, working on the house, exercise (even though I dislike exercise), beating a pillow, driving my car somewhere private and screaming.......there was a thread here not too long ago on how to deal with anger. Does anybody remember where that ended up?
Ultimately, you have to let his mom do whatever she's gonna do. Those are her choices, and sick as it is, you've got to let her make her own mistakes even if you think they're hurting your AH.
And your AH is gonna do whatever HE's gonna do too.
All you can do is stick by your boundaries ----- WAY TO GO, by the way
------ and turn your thoughts back to your own happiness whenever you can. Your happiness isn't 100% dependent on what he does or doesn't choose to do. You have other choices too, your OWN dreams besides helping to heal an alcoholic, and it might make you feel better in your mind and heart if you were to focus your attention there instead of on things you can't control.
But I know how you're feeling, and I'm sending you a big hug from here!
GL