They are worth it.
Everyone is. The pain they cause you won't go away, until you've accepted to love them anyways. This does not mean that you should spend all of your time with them, in-fact you should spend as little time with them as possible.
When you feel yourself thinking hateful spiteful thoughts, stop them, and replace them with love. Think of that person and force yourself to wish them happiness. If you can do this, then you have guaranteed yourself happiness. Because when you try to punish them, you are only punishing yourself.
"I the Lord will forgive whom I will forgive, but of you it is required to forgive all men."
-Doctrine and Covenants 64:10