Can I sue my manager for defamation of character, for a retaliatory performance evaluation?

My director resigned 3 days after I informed her that she was wrong for telling me that she was going to fire an employee after she informed her that she was bipolar. The director told me and other staff that she could not have another bipolar person in her day because her daughter is bipolar and she did not want to deal with it at work to. I told her that was wrong, and she should reconsider. She became upset, and from that point on, she was argumentative and challenging towards everything I said or did. There was a situation where we had joked about not making a particular decision again, and she flipped out, yelling, and pointing her finger in my face. I walked out of the office, to get away from her rage, and she screamed at me that I better not walk away. I stated that I was not comfortable with her hostile behavior, and asked her to stop yelling. She continued to scream and told me if I walked away she would fire me. I replied that I was going to contact HR and walked into my office. 3 days later she resigned. She gave 2 weeks notice, and her last day was the day performance appraisals were due. She wrote horrible lies, contradicting the letter of recommendation she wrote for me 3 months prior. She gave me less than 1 of 4 on many sections of the appraisal. When she submitted this to her manager for review, that manager contacted HR, knowing something did not look right. I have received an award for excellence based on my position, and in this appraisal, she stated that I have no Integrity, respect, I am a bully, and I am discriminatory towards my clients, and many more untrue, undocumented statements. All of these derogatory statements are without merit or documentation. I was never coached, warned, or provided any documentation of my terrible work performance. Her manager conducted the appraisal review with me, and it was so riddled with untruths, she went back to HR and made changes to my overall scores. However, the derogatory remarks remain in the performance appraisal. I was just denied a promotion the same week that this appraisal was reviewed with me, and I feel that is in direct correlation with the statements made against me. I would like to know if I may file a suit against the individual that wrote the appraisal, not my employer.