hostile work environment?

For almost 8 months now I have made several oral and written complaints to management of the company I work for about another employee (african american) that has been disrespectful to her boss and other employees, myself included (caucasian)and rude to clients. I have been told so many times to 'deal with it' because she is going to retire soon. Her supervisor has written her up many times in the last few months and she was also suspended for 3 days w/o pay for being rude to clients and insubordinate to her boss. The 'problem' co-worker sits at the desk behind me and constantly makes rude comments about other employees and says things like 'one day I will just not show up' or 'I will make this company pay, they can't do this because of my race'. She also constantly makes derogatory remarks about co-workers after they walk away. Yesterday, she insulted my intellegence, which I went to the President and said 'I need some time away until she retires, I can't deal with this anymore'. I am an outstanding employee and have documentation to prove it. I also recently starting seeing a doctor due to anxiety which they attributed to my work environment. After my meeting with the President, I was told by my boss, 'If you don't come back tomorrow, they will write you up and fire you'. I am not the only employee that has written complaints about this employee but I am the only employee that has demanded action on this problem and now I am being told I will be fired. Do I have a case?