I agree with SparkleKitty. You will reach a point where you are not so involved with him.
I think I am the only one with an extensive issue with my AH a pervert and I found out way later.
Once I discovered his filth it hurt so bad that it changed everything for me.
I could care less to talk to him now or even see him and as days go by it is better.
I slip back at times but have learned it's ok just keep going.
"I know I shouldn't care." This reminded me of when I tell myself im going on a diet, the first thing I think of is food and I then obsess with food lol.
We are not designed to be robots we have feeling and emotions but try to focus on that on you. Only you are getting hurt.