I am glad they figured out her issue and that she got/is getting treatment.
The thing about substance abuse is that so many times it is self treating what can be a serious personality disorder. That may be what you are seeing. For many, they think that when their qualifier stops abusing they will get better. So many times it just unmasks the true problem.
It's absolutely ok for you to step back and take care of yourself too. You know the saying about being in the airplane, you have to put the oxygen mask on yourself first if you are to be any help to those around you.
Hugs to you. Thank you for the update. We are here for you always!!!!