Don't worry so much about the letter stuff. Truthfully it's a bunch of baloney. I only had 1 letter from my primary therapist and one letter from a psychiatrist that I had a single session with. That's it. The primary therapist is the most important one, the other is not so important. The day after your surgery you are going to wake up and realize that the standards of care was a tempest in a tea cup.
Just do our thing, bide your time, do whatever they ask, and in what 6 months it will all be over. Then you will look back on all of these posts and laugh.
When I went to Canada no one even looked at those letters. They were put in a manila folder never to be seen again within the first 5 minutes. I was there, I made it and "I" was ready, that was what mattered.