I was divorced 15 years ago &hated my ex for many years...I really let her get under my skin. Two things helped: 1.) The kids grew up & left the nest so their mother's venom could no longer affect them. & 2.) It sounds stupid, but Im in AA. One of their suggestions is to pray (or whatever you do) & wish your ex the same things you wish for yourself. For some reason that minimized my hatred into mere dislike. She doesn't get under my skin anymore. Good luck.