Forgiveness is one of the foundations of Christianity. We are asked to forgive others and ourselves. Forgiveness is difficult to do but quite a release when you actually accomplish it.
However, forgiveness is not the same as forgetting. If someone in your past has hurt or abused you, in order to move on, you have to forgive that person, but that does not mean that you allow them back into your life to continue the negativity, drama and abuse. Life is far too short to spend it with people who make you miserable or physically ill. Especially when they are so entrenched in their own little bubble to see how their thoughtless words and actions affect others.