Remember mean spirited people are just the membrane through which Shaitan passes to cause you to despair.
Focus on the one that whispered and not the one who spoke the whisper. This will make forgiveness easier.
If you were to condense the reasons behind every harm shaitan wishes to cause you, you would see that it is to cause you to despair in Allah, create distance between you and Him and destroy yourself.
People who harm usually do so out of insecurity, to prove their worth, anger and envy and there are limits to their malice. Shaitan has no limits and wishes to see you destroyed. The mission of insan is to feel better about himself but the mission of Shaitan is to see you destroyed. Never forget that.