Hi
I understand your feelings; I too have felt this way.
A question was posed to me: "What is your pay off from holding onto these emotions?" I found this to be true. If you think really hard, this will be some type of "pay off" for you. It might be that by feeling resentful of this person, you are justifying to yourself that you are "right" and the other person is "wong". Something like this...
Also, your feelings are only costing ONE person - and that's you. So "get over it" for YOUR sake, if not for anyone else's.
Remember, forgiveness doesn't mean you are condoning whatever he/she did to you. It just means that you've decided to move on with your life......
Good luck. It's not as hard as it may seem. It's just a decision which is easy to stick to, once you've REALLY decided to move on.... Do it for YOU.