Bluebelle has given tried and tested advice.
Many years ago, I worked for someone who was really horrible to her team. There was very little we could do about it, except... One day we made a cut-out of 'gingerbread men' type figures, so that it unfolded into a long chain. On each of the (joined up) figures, we wrote her name. We held this long chain, and said loudly and firmly how much we disliked her and how horrible she was. Then we fed it into the shredding machine.
I can't even begin to tell you how good it felt, to see her come out in shreds at the other end (well, you know, not literally in person!). It made us all feel a lot more positive about our situation, and even though she continued to be horrible, we were different people and able to deal better with her.