Sorry to hear you are going through such a difficult time, Purple.

I can think of at least 3 options:
1) Wait and see if your evil boss changes her behavior. Sometimes getting it all out brings real change.
2) Continue business as usual as if it didn't happen.
3) Start planning how you might escape this job. Look for new opportunities while coping with the evil one.

This happened to me in a previous job and I did a combination of 2 and 3. I got angry at my boss and said a few things, then I said "I've had it" and stormed out of the room. He never mentioned it and strangely, things just continued. Unfortunately, nothing really changed (except I left that job later on). I was glad I did get angry, because I felt mistreated and it made me feel good to let him know it. I am usually quiet and calm (on the outside) at work, so it wasn't like me and must have shocked him.

I hope it gets better for you.