If you are struggling to let go of something, then writing down your thoughts and feelings in a journal can often be a big help. You can do this directly or write it in the form of a letter to your future self if you prefer. Another good idea is to write down your journey towards acceptance as a story with a character who feels as you do. It helps you to disassociate yourself with your experience and see it for what it is, and getting a more removed perspective on a situation can help bring clarity and thereby facilitate letting go.