There are people in my industry who totally screwed up my career and my life. One of them was a genuine psychopath; I had no idea how do deal with him because dealing with his behavior and lack of feelings is so outside anything most people have ever experienced.

I still hate the people who messed me up, but there's really nothing I can do about it. I would be very very careful you don't put yourself in danger. In fact, I think the safest thing is to let it go. If they behaved the way you said they did then they are not above doing absolutely anything to get back at you. What you're talking about isn't exactly the same thing as losing weight because your ex-husband cheated on you.