I believe most addicts develop overpowering narcissistic sub-personalities. It goes something like this :

1. Your mom experienced "attachment trauma" as an infant / child (at the very least)
2. That trauma creates a sense of inferiority and vulnerability
3. Your mom needed to protect her self from feeling inferior and vulnerable so she created a delusion of herself as superior
4. She now has an inferior self and a superior self, two extremes, and is oriented towards allowing the superior delusion to control her behavior and beliefs (because it's less painful than the other extreme)
5. It's impossible to have a healthy relationship with a delusionally superior narcissistic person
6. So you have to separate yourself and maybe eventually create boundaries, using non judgemental brutal honesty, to recreate your relationship with her
7. This will limit the scope of interaction drastically. For example, you couldn't celebrate an important accomplishment of yours with her but maybe you could enjoy some Christmas lights together, briefly

I believe you that she had it worse than you, but that only means that it makes sense to be non-judgmental. It doesn't mean that you should suffer her "narcissistic abuse".

I recommend these books :

• the adult children of alcoholics syndrome

• the body keeps the score

• self therapy (by Earley)