Worse than anger?
Anger hurts, and anger hurts us back. What could possibly be a worse sentiment to carry than anger?
You will not be punished for your anger, you will be punished by your anger – Buddha
Holding on to anger is like grasping a hot coal with the intent of throwing it at someone else; you are the one who gets burned – Buddha
Anger hurts, there are few arguments to the contrary in either ancient or modern philosophy.