What can I do if the whole office is harassing me, retailiating against me, & defamation of me?

I have Bipolar Disorder and ADHD. I am on Meds and see a Doctor. Two years ago, I became Manic. There was a lot of stressful things in my life. Even though I have a Domestic Partner, I felt alone at that time in my life. With being Manic you can become Hypersexual. This is what happened to me. I began sitting on a personal massager in my car. I never was exposed in any way or did this with the intention of adults or kids to see me. I did this in the parking lot of my job on my lunch. Co-workers saw me. I then realized what I had done. I went to the Doctor and got my Meds changed. I also started therapy. I stopped doing this Feb. of 2009, and have not done it again to this day. I informed the head boss what I had done. She said because I did not do it inside, it was not a big deal. Co-workers did not agree. They harassed me at work and followed me everywhere outside of work. They spread a video that they taped of me when I use to do this. HR transfered me to a new office in hopes of a new start. However, the old office told them. The Co-workers now started at the new office. I went out on two stress leaves. After they put me through a second evaluation with one of their Doctors, I was released to go back to the office. Co-workers where upset to see me return, after being investigated for their harassment. They retaliated against me. They made an altered video of me, and said that I was sitting on a massager in my car again. This time they even talked kids into saying that they saw me. I have never done this since I got help for it in Feb. 2009. They are spreading these lies in other offices and on the street. They are showing there fake video to everyone and anyone. This includes HR. They have tried to make me seem like a pervert and get me arrested. They failed at this. Now they are trying to upset me enough to say that I am not well, and get an emergency mental mobile unit to take me and put me on a 72 hr. lock down. Everyday I go to this hostile work enviorment to support my family. I deal with their harassment, humiliation, retaliation, and defamation everyday. It is hard to keep up with my work due to this. The worst part is...I can not go to any management in my office because they are all in it too. They are all trying to get HR to fire me. I have not done anything wrong. Please help me...if you can?