A happy update
To make a long story short, I quit my terrible boss last year after a devastating performance review and the discovery of a hateful burn book she was keeping about all my alleged faults.
The stars aligned so that I accepted a new offer the literal day before she decided to go off on another petty campaign against me. I already had my two week notice in draft, and was able to quit right as she was gathering steam for yet another episode of unprofessional behavior—within an hour of the first outburst, in fact! One of my coworkers was convinced I had rage quit without anything lined up because of how quickly I quit after she exploded on me.
I've just hit the six month mark at my new job and things couldn't be better. I'm respected for my expertise in the field, nobody starts weird competitions with me or tries to one up everything I do, people act and speak like adults, and I just had a **terrific first performance review** with full "exceeds expectations" across the board. It's really boosted my self confidence after the way my ex nBoss spoke about my performance and abilities last year!