The Bible says we are to forgive "seven times seventy" times -- effectively, "infinity" times.
That being said, forgiveness is an intensely personal thing, and between you, your God and your own conscience. I wasn't even telling you to FORGIVE; I was trying to encourage you to just show some basic COMPASSION and COMMON COURTESY.
You have every right to not want to. But you can be "right" and still have it eat at your insides.