How to get over the pain, anger, and bitterness of being a victim of bullying?

I was bullied a lot. I started to forget about them in my early twenties. I realized at some point when I was a mom that my bullies were actually just kids who must have had a lot of problems in their life to pick on me the way they did when they didn’t even know me. All of my bullies never knew me and that’s what I find so odd. Like I was this random kid they all decided to hate. When I discovered Facebook I looked up the worst bully I ever had. Her name was Casey. She was a year older than me. Her Facebook picture was awful. She would have been early forties in the picture but she looked in her sixties. The years have not been good to her. She looked like she was missing front teeth and her skin was wrinkly.