I think you need to address moving on completely with your therapist. I don’t know when you broke up with him, but your original post was from six months ago. Over analyzing his letter and this relationship is not doing you any favors right now. You need to stop going over the past and move forward. Burn the letters (safely) or throw them out. Stop reading them. Every time you think of him, redirect your thoughts. Consciously choose not to give him more of your emotional energy. He doesn’t deserve this much space in your thoughts. You need to work on your self esteem and confidence. If your therapist isn’t working for you, you should look for a new one.