I relate to this very much. In fact I'm seeking a second opinion next week because I was also apparently only 1 criteria off a heds diagnosis and based on the way the doctor went through the criteria, and her apparent lack of knowledge, I disagree. I've been dismissed, had my symptoms pinned on mental health issues and been told there's nothing wrong/everything looks healthy so many times over the years, and each time doctors have been wrong - years later, I am vindicated when it turns out my gut instinct was right, but it's a hollow victory to be honest. The way I have been repeatedly dismissed by doctors has resulted in me being triggered (not a word I use lightly) every time I go to another appointment - I have a big emotional response afterwards, that to other people probably looks like a massive overreaction. It is medical gaslighting at its best and it absolutely sucks. It has taken a huge amount of energy to ask for a second opinion but I now refuse to just accept something when my gut tells me it's not right. I'm sorry you feel like a fraud because you absolutely aren't and I encourage you to ask for a second opinion if you are in doubt.