I’m never able to forgive someone truly. I do intend to forgive and forget and I even say that I forgive you and I don’t even intend anything bad for them. But deep down, I never forgive them and I have no idea why. It always lurks. Why is it this way? How do I overcome this?

Generally speaking we get extremely affected by peoples behavior towards us because of our ego. Kebr or arrogance does not allow us to forgive. We should ask ourselves a question, who am I?
When people harm as they are disobeying God himself, He forgives and so we should especially if we want to be forgiven