Gee, that really is beat Maybe you already have, but have you spoke with your boss about this? Is your boss okay to talk to about how this is really upsetting you?
If you can, try to discuss this with him/her, I found many years ago that even if I felt my boss didn't want to hear me or would get annoyed, he actually surprised me and talked to me about things that were happening at work and with employees or customer's accounts.
Most of the times things worked out for the best and all ran smoothly, the one's that caused trouble were the ones that not many of the other co-workers got along with either and were let go or quit and went elsewhere, which benefited everyone in the long run.
Just my 2 cents. I'm wishing you lots of luck with this situation, I know how things like this can really drain a person, hang in there

"darkeyes"

In giving advice seek to help, not please your friend
SOLON