When I told the kids about the dissolution and the attorney, they both responded, "Oh, we thought you were already divorced."
Completely anti-climatic. I think kids sometimes have a better grasp of the situation than we do. Your kids know that their dad is not being a husband right now. They know it's unlikely you will get back together.
As for the letter, I don't see it giving you the response/reaction you are looking for right now. Detach Will. I know how hard this is. I do.
What about the ol' rubberband trick. Snap it when you think of H. Maybe it's time to push him outta your thoughts some. Seems like he is still front and center.
You CAN DO THIS. YOU CAN TAKE CARE OF YOURSELF. If I can, you can too. :-)
"You know, it's times like these when I realize what a superhero I am." Tony Stark/Iron Man
“Focus on what you can do, then do it with all your heart.” Lois Wilson