I think its all in the willingness to forgive. Go to God. Let Him know your true feeling. Say something like this, I hate what he/she did, I do not like the hurt that this person caused, God if it were up to me I would not forgive them, but I know it is not up to me and because you love and forgave me, I give you this whole stinking situation. I am tired of it all anyway. If you want me to forgive, I confess, I cannot do it. I am willing however, to let You do it through me. Today, I give it to you and ask that you do what needs to be done. And, if you want me to love this person, I will be your pawn. Love and forgive them through me. Replace these awful feelings with your peace and love. Thank-you Lord for taking over this problem. I will no longer worry about it because it belongs to you now. Thank-you for the release.
The words do not have to be exactly like that. Just be real with the Lord. He knows how you feel anyway. No sense in hiding it. You have nothing to loose but everything to gain......His peace!
God bless you in this situation!