I think it is up to you to decide if there is truth in what they said or not. Even if said in anger and they apologize there still may be truth in it. Accepting apologies and forgiving is a great thing. It takes a mature person to do that. It takes an even more mature person to examine what may be true or not be true in what they said. Self examination is a hard thing. The fact they said it doesn't make it true. You would have to honestly look at the evidence on both sides. If someone said you were worthless than dismiss it as false right away. If someone said you are sometimes snobbish or withdrawn or something then maybe take a look at it.

If everything sticks as truth not matter what is said then I am not sure. That would sound like a self esteem issue and putting to much value in what others think and say. Your self worth doesn't come from what others think.