Many people can struggle with resentment. Wikipedia defines resentment as the experience of a negative emotion (anger or hatred for instance) felt as a result of a real or imagined wrong done. To move forward in your life you must get past resentment. This is why this is a key component in the 12 steps of recovery.
The first step to resolving resentment is to acknowledge there is a wound. Many people minimize or deny the affects of their hurt. It feels clichéd to blame one’s problems on something that happened in the past. However, until you acknowledge there is a wound you cannot heal it. Once you have identified the cause of your resentment you need to work through the emotions associated with it. How do you do this? You work through emotions by allowing yourself to have them. Let yourself be angry and sad and whatever else comes up. To push your feelings down usually means having to deal with anxiety or depression later. You can experience your feelings by writing about them, talking about them, or by just sitting with them.
When you have felt your emotions you can find forgiveness. Forgiveness is not letting the person off the hook for hurting you, it is letting go of the anger you hold towards them. Carrying resentment hurts you and the people that are important to you. Allow yourself to release it and you will live a happier life.