Well, I know from my own situation, that keeping as much distance as possible (not really possible
), and trying to keep some humor about the situation- even the smallest thread of humor- helps. Like I said, my personal "office monster" is a constant complainer. One day, I kept a little sheet of paper on my desk and put a mark for every negative remark she made- I got up to 45 in the first half of my shift. Even knowing her, I was shocked. For some reason, ever since then, I find the complaints to be just a little bit funny. Not "ha ha" funny, more like black humor. They still aren't pleasant, but it's taken a bit of the edge off.
If humor just isn't possible, and you are not able to physically separate yourself from her during working hours, there are 2 things that I use in other unpleasant situations. One: the "happy place". Yes, I know it's hokey, but developing a pleasant thought, a little story or daydream, a visualization of excape can be helpful. Of course, the opposite: the "unhappy place" where you can mentally place
her might also be tempting, but I'd advise that only in the most dire circumstances.
The other is based on the Taoist philosophy that problems only exist when we except them, or percieve them as problems. Example: two men are in jail. One of them rails against his fate: he fights, he pushes, he feels sorry for himself, he feels every moment there as a torment. The other man, living under the same conditions excepts his fate, but refuses to except the fate as a problem: he goes with the flow, finds what pleasure he can in the circumstance, strives to better himself with the same intensity that he had on the outside. He does not rail or fight back, and because of this he is able to find peace.
Am I able to use either of these to completely protect myself? No, not all of the time... but I think that I'm successful often enough that I've found a bit of equillibrium. I certainly haven't been driven to quit or kill, and that's always a plus!
I would say this: you will not be able to change her- so that leaves three options- change yourself (or at least your perceptions of the situation), remove yourself from the situation physically or mentally, or suffer with the consequences of contact. Whichever you choose, I wish you great strength, and please feel free to vent all you need- an emotion let go is so much better then one held in.