Quite frankly I'm happy the man my ex-wife had an affair with quit his job.
Is there anything you're hoping happens to this man?
I hope he will remain unemployed for the rest of his life because of the betrayal
It's natural to hold onto grudges when someone has hurt you badly. If you hold onto these grudges too long though people will begin to believe that you are petty.
I only hope he is dead. I want to kill him.
Your feeling of betrayal is understandable, but wanting to kill this man is not a rational response. Your extreme grudge is going to end up harming you and prevent you from moving on and finding peace. Have you thought about seeking therapy because of this negative experience?