The book by Lewis B. Smedes – ‘The Art of Forgiving: When You Need to Forgive and Don’t Know how’ is a good guide.

The practice of mindfulness might be a good place to start. Practice noticing when your thoughts become obsessive and fixated on the ‘story and feeling of being rejected’. The trick here is to notice without judging and labeling and in this way remaining a detached observer.

Detachment is not the same as Indifference so notice how your thoughts ‘affect’ you. What emotions come to the surface. As an observer you notice the emotions without becoming the emotion. Perhaps you notice the thoughts are connected to the emotion of sadness or fear, or resentment… without “becoming sad”, fearful or resentful.  The observer remains a still point of compassion, for yourself and others – in that space forgiveness becomes possible (forgiveness is a letting go not a forgetting. You mourn what you experienced as a loss, lean into it and step forward).

As an observer to your thoughts check them for cognitive distortions. What is it you know and what thoughts are based on imaginings.

For example. A part of your story is that had you been held by your birth parents you would now be free of a fear of rejection and so emotionally healthy. Notice that these thoughts are speculative, you do not know, and the story would not stop at that point. So, continue the story. Your birth parents kept you but their fears of not being able to care for you were real. They loved you but could not care or provide for you as your adoptive parents did. Perhaps there were days you went hungry and limited education possibilities that let you fall though the cracks. In stead of a fear of rejection you became angry and envious of others…. Statistically that is the more likely story then the one you have been telling.

If there comes a time when you overcome your obsessive thoughts of rejection and not being good enough. As an observer you will notice that the solution occurred the moment you stopped and took responsibility for your thoughts and how you direct your consciousness.  You will have realized that you are not your past or your thoughts or your consciousness but director of thoughts and your consciousness. You can spend another 10 years digging into your past to get to that point or you can start today. I cannot change what happened to me, I have mourned what could not be. I chose to move forward from where I am (which is the only place any of us can move from)