You sound a lot like I did before I really started to confront my internalized ableism and worked with a I also saw terms like "autism" and "ADHD" as insulting in some way, tried to separate myself from being lumped in with these groups and figured I would get along better and have more opportunities as someone (mostly) perceived completely non-disabled, but just a bit eccentric.

Additionally, like you, multiple professionals from multiple disciplines thought there was absolutely no way for me to be autistic. I even hid somewhat behind these opinions as "proof" I couldn't be autistic, which counted me out of the club due to reasons like being an early talker, being able to schedule my own appointments, being "too smart and too good a student", getting my first evaluation at 18 (and specifically after age 5), my special interests being "too socially acceptable", and not immediately walking into a room and immediately trashing it, among other things. I would even cite examples of classmates and other people I knew who were either non or minimally speaking, unable to bathe without assistance, extremely prone to explosive, very public meltdowns, and/or completely uninterested in friendship, and assert how I was "nothing like these people".

I used to get incredibly defensive anytime someone suggested I "get checked out", reminded them of some autistic person they knew, or compared me to Sheldon Cooper. I perceived a rather dichotomous relationship between the skills and milestones people referred to when stroking my ego and labeling me a "gifted" child and autism.

At some point, the wall I had erected crumbled and I felt I had no other choice but to figure out what else could be going on besides being a "quirky genius". I had started dating and knew that there had to be a reason I had so little tolerance for anything physical in the relationship besides me having a much lower sex drive than my partner.

I wanted to know why I suddenly started to get Cs midway through undergrad after having been a repeat grade skipper with a 4.2 GPA and eventually hit a glass ceiling whereby I had two degrees and zero professional network. I got extremely fed up and embarrassed by living with my parents, getting rejected from grad school and job interviews over and over with no end in sight, and having no driver's license in my early 20's in a city with horrible public transportation (it's truly a feeling like no other to be in your last year of college being driven on campus and dropped off by your mom). I simply could no longer buy that it was all because I was "so smart" and "didn't apply myself".

The turning point in terms of diagnosis was a psychiatrist who convinced me I could still be autistic despite having started to speak at the age of 9 months after I showed her an at least 100-page symptom diary I had put together after I had become convinced I might end up on one of those mystery diagnosis reality shows one day.

You might change your mind, you might not. Just know that I reading this felt like opening a time capsule for myself in a lot of ways.