It seems to me that your trust is damaged with regard to this person. If so, please keep in mind that as you forgive, you do not have to trust at first. Trust comes when you are ready to reconcile. If this insight does not help, then please re-think your level of anger. Perhaps you are more angry than you realize. If this is so, try to forgive the person for a lesser offense. Another strategy is to begin the forgiveness process with a less challenging person. As you learn to forgive this person, you may become stronger in your forgiveness and then be able to deal with this more challenging person and his or her difficult offense against you. A key is to retain a strong will to forgive.