Please don't do that to yourself, Anika. You did what was necessary to protect everyone in that working environment.

Management needs to know what is going on. Just what you have told us is what you should report to them when they ask: failure to work her load of the job; disappearance from the work scene; trying to be authoritative with co-workers;
unstable in emotions.

You are the one who is sensitive to other people; she is not. That's a quality that is important in any work environment: self-respect and consequently respect for others. (Frankly, that's why so many aggressive and negative people fall apart when their behavior is really confronted by stronger people.)

Take care and try not to worry. You'll get help in your observations.