What should I do about a boss with a personality disorder?

I am working a retail job, been there going on my 2nd week. The boss, during an unloading of a truck in our retail environment, stepped over to me and loudly proclaimed that I am working too slowly (when I was working the same speed as others). She dragged over a trash dumpster and said I should throw my empty boxes there so as to be faster. You cannot move like this (she demonstrated a speed at which I have never moved accept when I had the flu). What do you do with a person like this when they go out of