Personal Opinion Only: I respect those whose ethics "require" forgiveness.
I do not believe true forgiveness can be forced. Either it grows and matures on its own or it does not. I cannot "affirm" it into existence. I might be able to drown feelings of unforgiveness in all sorts of mental exercises (mental tricks?) - or substances, but plastering over something is not really erasing it. I prefer to attempt to stand back from the whole situation and consider it in all its complexities, to the extent a very finite individual can.