Search Results: how to treat an ex

A few years ago, my ex came back into my life after breaking up with me because of her religion. We didn't speak for two years, and that night we were on the phone almost 6 hours.
After a few weeks of talking, I told her I still had feelings for her, and I couldn't just be friends. She didn't understand, and it was at that point I told her I had been in love with her. Then it clicked for her.
Over the next year, we dated, she fell in love with me and she made an attempt to make the relationship work. I even proposed to her. Then she decided to go on a mission.
She broke up with me after a few months, then spent two months trying to convert me. She stopped responding to me, and when she came back, I tried talking to her. She accused me of doing things and treating her in ways I didn't do. She blamed the whole relationship failing on me. She saw nothing wrong with what she did, and just talked down to me.
I couldn't understand why she'd treat me so horrible if she loved me. But she got married less than 6 months after returning.
Since then, I turned myself around. I have a new girlfriend, I've gotten into good shape, and grew out a beard and keep up with myself. I've seen her in passing, and she always gives me an unusual look.
My friends say she give me 'I miss you eyes' but I don't see that, but I'm not too concerned either.
At the same time, I hold great pain, anger and resentment towards her for what she did and I haven't been able to let it go even a year later. I feel she shouldn't be forgiven for how she treated me, but I'm so angry whenever I'm around her because of the pain she brought me.
In this circumstance, is it wrong to not forgive someone?