Maybe we need to let go, for hanging on to unforgiveness is just keeping the situation 'alive'. Like living in the past, you can't move forward. I don't think forgiving is 'forgetting', but it will help in letting go of hurt feelings, anger or pain felt.
If we recognize it is not about them and concentrate on you, we can then see that forgiving someone is a gift for our self. Don't wait for an apology. When we forgive, we aren't saying we forgive their actions or words, but forgive the person.
It's not easy to forgive someone and it will take time. Allow yourself that time and don't be so hard on yourself. Go through the stages and give yourself the gift of forgiving.
Did you ever hurt someone? Do you remember how you felt when that person forgave you?
Maybe you will never know why they hurt you, what the motivation behind their words or actions were. If we all try to expand our thought process and learn to see the shoe on the other foot, we will consider forgiving more easily.
According to wikipedia:
Forgiveness is the mental, and/or spiritual process of ceasing to feel resentment, indignation or anger against another person for a perceived offence, difference or mistake, or ceasing to demand punishment or restitution.
The power in forgiveness is to replace what has been lost or stolen and remove the fear of being injured again, to liberate from the slavery of resentment, bitterness, hatred, malice, fear, and a consumed life of distrust