Tips on preparing for tough appointments?

I (22F) have a neurology appointment in a couple of weeks. I am finally putting my foot down and fighting. This is my 5th neurologist and nobody has had any answers as to what is wrong, why it is happening, or why I am not responding to a single medication. Confrontation almost always makes me cry from nerves, and this always gets me labelled as a "mental health" patient not a neuro patient, therefore I am never taken seriously. Any tips for standing up for yourself in difficult appointments where you know you will struggle to be heard?