Unforgiveness is a sin. It blocks some blessings from flowing to you from God.
Unforgiveness is a prison. It is a prison to which you hold the key. Use the key of forgiveness and let yourself out.
Unforgiveness is the work of ego against God. Let it go. The freedom you experience will be far more pleasurable.
And when you stand praying, if you hold anything against anyone, forgive him, so that your Father in heaven may forgive you your sins. (Mark 11:25)
Get out at all costs. Get help to get out if necessary. Forgive. Forgive. Forgive. No matter what.
Forgiving does not mean forgetting. Forgiving does not mean giving in. Forgiving means appropriately provide opportunity for restoration.
Once you have forgiven, share your testimony of the good feelings that resulted.