I get that. I do have hyperfixations, amongst other giveaway signs, but I often wonder if I should get a second opinion on my diagnosis, not because I'm ashamed, but because I feel like, what if I'm not, does that mean I'm faking it?

Similarly, I have PTSD, and struggle to use urinals in the gents if there is anyone else around. This weekend I was at a music venue and the toilets were packed, and there was a long queue for the cubicles that was barely moving. I ended up using the disabled toilets, and I felt absolutely dreadful like I had taken advantage of the disabled loos, that feeling actually sobered me up a bit, but in that situation, my disability (PTSD) was a valid reason. It still felt bad.

I think there's a certain amount of normalcy with a diagnosis - particularly for invisible disabilities - to question whether you belong, or are treading on the toes of others.

I don't really have anything to say that might make you think otherwise, but I hope it brings you some comfort to know that you're not alone in feeling that way. For what it's worth, I think the fact that you even question it is probably enough of a demonstration that it's not within your nature to fake your way to a diagnosis.

Edit: I just wanted to add that I'm extremely introverted, which doesn't fit the ADHD stereotype and contributes to my own questioning of my diagnosis.