I agree with Hockey. A Neuro Psych Assessment would be a good start. With such a report in hand, you can overcome the objections of the disbelieving doctors.

You sound like me in that I do much better on the keyboard that talking. On the keyboard, I can reread what I am typing to edit and stay on thought.

It is important to find providers (PT and otherwise) who believe in you and don't cause frustration and stress.

I am not sure of what help you are asking for except help getting across to doctors.