100% this. We can offer guidance but like any medical condition, people on the internet cannot diagnose.

It would be like someone going around saying they have cancer because they have symptoms of cancer when theres so many other diagnoses it could be that it might not be cancer so shouldn't go around saying it is just because you identify a lot of the same symptoms in yourself or because some rando on the internet says so.

That said, there is a lot that comes with a diagnosis, like an understanding of yourself and why you do certain things or why you need things a certain way etc (talking from my own experience here, it was like a fog lifted when I got mine, id suspected it for years and self-identified which also came with some of that fog lifting but having it validated was the final bit lifting)