Rancor

He who will not curb his passion, will wish that undone which his grief and resentment suggested, while he violently plies his revenge with unsated rancor. Rage is a short madness. Rule your passion, which commands, if it do not obey; do not restrain it with a bridle, and with fetters.

If you are not already dead, forgive. Rancor is heavy, it is worldly; leave it on earth: die light.

But he who dies in despair has lived his whole life in vain.