Whenever we are tempted to hold grudges, we do well to remember the servant in Matthew 18:23-35. When we choose not to forgive, God sees us as the unforgiving servant in the parable.
But by releasing our own “prisoners,” we open our hearts for God to release us from our prisons. We often feel a sense of relief when we forgive people and let go. This relief happens because we just got out of the prison we kept ourselves.
My final advice is this: when it’s difficult to forgive, ask God for the grace to do so.
God bless you.