I agree with busto. The letter is very, very long. You explicitly state that you are doing it to teach H a lesson of what the process will involve. You need to let the process teach H the lesson. All of that stuff in there detailing the process should come from his L, not you. In some other older threads, vets mentioned leaving all of the D stuff to the Ls, so it keeps it separate from your R while you continue DB'ing, being upbeat and approachable, etc. This letter is the opposite of upbeat and approachable.
Don't apologize for your situation in the letter, either. That's pursuing again.