HSSH

So not a lot to say today. I went over parents I guess I'll go over love number one.
We'll call him hssh, high school sweetheart.
We met my sophomore year, and quickly became an item. We dated for two and a half years, married, three years later had a child, and three years later we were divorced.
I'd never dated anyone before him. I mean I was only 15. I'd had "boyfriends" but nothing serious and nothing really in high school. I wan't part of the "in" crowd, or any crowd really. Not much has changed.
I didn't realize how controlling, and possessive he was. I guessed after living with my father, his behavior seemed normal. 
He also was never around. He didn't make time for me or my boy. Our marriage wasn't awful it just wasn't much of a marriage. 
I thought I'd forgiven him. I'm realizing there is still some anger and resentment. He made promises. He didn't keep them. I didn't either. 
There's really not much to say. The thing to say is the wounds are still bleeding. They shouldn't be. 
It's been 20 years. How do I stop the bleeding?