Your letter is not about your ex being a d*ck. If he were a d*ck, you would have stopped thinking about him by now. But you are thinking about him. Almost a year later, and you're reaching out to me, too. You said you shouldn't be thinking about him though. Has someone told you that? Often our friends do.
Do it. Shine your light. If you don't, you could greatly diminish someone else's ability to find their own light. Through allowing your best self to shine you'll likely transform many lives in ways you cannot even begin to imagine. You could be the change this world needs to see to heal itself- don't deprive us of your light.
I am always fascinated about people's strengths and how they can enable a person to be at their best, to flourish and to fulfill their potential. This fascination was what led me to research about strengths and how people thrive, so that I could work with individuals and organisations to apply their strengths, in order to succeed.