Granite- nice letter, really.
Ive read your previous post as well and was not sure about writing my opinion.
But here it goes...
I think children are born trusting. They don't know any better. As you have said, they are dependant on others. They must trust that the care provider will do what is best for them. I highly doubt you were born any different. It is in human nature, even grown ppl can behave like that to ensure their survival (Stockholm syndrome).
We see our child self through adults eyes. That can cause problems. I think what your T is trying to do, is make you see yourself as the child you were. It is an important step in therapy.
Still I think you two should discuss this more. Letter is always a great way to communicate our feelings and emotions.