The most imporant thing on your spiritual journey and self healing is the radical self forgiveness.
When someone hurt you, betrayed you or did wrong by you, the imporant thing is not so much to forgive them, but to forgive yourself, that something within you created such situation.
Forgiveness is something you do for you, not for the person that left the pain behind.
You are forgiving yourself and healing the pain that was already within you and they were just there to trigger it and escavate it.
It's hard for the mind to understand this concept, because we were always taught that everything that happens to us comes from outside. When outside is just the mirror reflection of the inside.
The forgiveness and healing happens between the parts of yourself - between the human and the divine, between your ego and your soul, between inner child and an adult, between feminine and masculine sides of you.
The best mantra that I discovered for this is from ancient Hawaiian tradition called Ho'oponopono.
There are 4 phrases that you repeat to yourself, to forgive yourself. You can do it everytime you feel hurt and resentement.
I love you.
I am sorry.
Please forgive me.