At a loss for words

I don't even know what to do anymore. I just finished writing a letter to one of my closest friends, detailing in full why I am no longer satisfied with my job: it seems this business has a bad habit of attracting people who no one can win with- people who let everything get to them and take it out on whoever is closest. But this person I am dealing with now is the tops. I've dealt with her the longest, but the problem has gotten to me the shortest. I'm trying to let it go, and block it off from getting to me, but what can you do when no matter what you do nothing is good enough. Honestly, I was more ready to walk out today than I ever was at any point before.
Tip- Never work at a small business where the boss dates the office manager, and there is no inbetween person to discuss issues with.