Does your inner monologue sound like this?
“If the person who caused me pain could only see what they’d done, they would want to say they were sorry.”
What to do instead: It’s hard to swallow, but the person may never recognize what they’ve done. Acceptance and letting go are key aspects of forgiveness. A time-tested way to do this is to write them a letter that you do not intend to send. Do this with the ultimate intention of destroying it and letting go of its contents.