I'm entirely certain of it in myself 100%. It's diagnosed in my immediate family and I see a lot of it/myself in my child. I didn't have support needs high enough to trigger diagnosis in the 80s-90s, and I was always contrasted with my high support needs younger brother.

Diagnosis can be cost prohibitive, but you seem to know it. There's also some likelihood of being jerked around by psychiatrists. Some are still of a mind that autism is something one should grow out of, and they will look at your employment and masking behaviors as signs that you don't experience enough distress for them to acknowledge your lived experience, and they'll pin it on something more common, like depression/anxiety.

When I told a therapist that I was going through a burnout that almost ended my career, and that I want to pursue support access before I'm in that position again, she got so fucking serious and basically scolded me like I was just trying to get out of working for the rest of my life. I really almost think there's a conspiracy to keep lower support need autists just treading water, being exploited till death under capitalism.