You must face her by first standing up for yourself.
This is what I did... I didn't let her push me around and rage at me... I raged right back at her. I yelled back. I fought back... It didn't make one bit of difference. All that did was escalate her anger and escalate arguments into breakups. Then she called me the abusive one...
Closer to the end, I tried reasoning, agreeing to disagree, and sometimes didn't react at all... That didn't work either.
Nothing works.
EVEN WHEN THEY ARE BEING TREATED!
Mine was heavily medicated and diagnosed in her late teens... It DOES NOT help.