I'm dealing with a coworker who has serious issues too. It is a "hostile work enviornment" and you have employee rights at the federal level also. You can contact the (NLRB) National Labor Relations Board if your employer fails to address the issue. It is grounds for a lawsuit. I am quite sure your employer does not want the NLRB investigating their business.
Good luck, and you should not have to quit your job and go elsewhere. Make management deal with the problem.