Struggling to forgive

Last year, I had posted on here about how I told my boyfriend’s wife that he was cheating on her. For context, he had lied to me about his marital status. The wife had no idea about anything. When I found out, I ended things and told the wife. I cut him out of my life completely and haven’t spoken to him in about a year.

During this time, I have really struggled to move on from this hurt. I have felt like a loser, and pushover (why else would someone be able to take me for a ride, why else would I ignore some of the red flags, and etc etc).

I continue to hate that man vehemently. During this time, I have also struggled to form any meaningful romantic relationships. I know that I will need to invest in therapy to get over this - but I would like some support from you women as well.

Worse still, I recently I ran into him at an event. Seeing him after a year has just brought back all those memories again and exacerbated the hurt.

I don’t know how to forgive because I don’t know what forgiveness means. I really don’t know how to let go. I’m just tired of being angry and want to figure out a way to stop being hateful towards him. How do I get past this?