Tired of My Job!

Ok, I don't gripe often, but I just think that I have put up with rude people for way too long! Have you ever worked with someone that every time you see them you either want to turn around and walk out of your job or just tear your hair out? I have, this someone is driving me nuts. I really don't like to fight with people or even have confrontation with people, so I just keep to myself. I don't say what I think or how I feel and it eats at me and eats at me until I just want to explode. I am at that point right now. I don't know what to do, I have been desperately trying to find another job. I have even been applying at places I don't really even want to work at, but I just don't know what to do anymore. If anyone has suggestions on what to do, let me know. I could really use the help before I say something that will get me fired :D.