What can I do about bullying in the work place?

In July 2013, I went to work on a team where the boss didn't want me. He was very hostile to me, and especially so in October when I broke down on the anniversary of my daughter's death. In December, I was admitted to in-patient care after I suffered a nervous breakdown due to his emotional bullying. I had been telling my HR rep since August about my boss' hostility, but he took no action and was impassive when I submitted a statement from within the hospital to describe why I was claiming Leave of Absence. I returned to work January 6, 2014 after extensive counseling. My boss returned from his vacation the following Monday, and two days later I was accused of being "racially insensitive" (the person who was supposedly upset at me submitted a statement saying she was not and had no idea what was going on), and that I had disobeyed a directive he left for my return. In truth I did misunderstand his direction, but I can show he took no steps to inform me of my mistake until the disciplinary action. On Feb. 13, I was suddenly transferred to another group. That seemed to be a good thing but on February 28, I was disciplined by my new boss. Her reasons: I am too sarcastic, someone rolled their eyes when referring to me (showing displeasure, apparently), another person was upset that I couldn't remember his name, and my shirt looked too much like a T-shirt which is prohibited clothing. Since joining this company three years ago my performance reviews have been "Exceeds Expectations" and I have performed all of my tasks under time and budget. Help!