One of the emotions we may feel when we are holding unforgiveness in our soul is anger. Sister, I want you to know that you are not wrong to feel angry.
God gave us a soul that comes with emotions. So we have to ask, "what is the usefulness of anger?" or "what is this anger saying about what I want?"
I wrestled with "letting go" because I was still angry. I learned that Forgiveness is not the absence of anger. Forgiveness is the choice to let go of the fault and the person who did it, not to let go of anger.
We have to deal with anger at the root and allow God's truth and love to heal us from the inside out.