I was diagnosed at 16 years old with high function autism spectrum disorder (ASD).
I did like half adult test, half children test. I may have to get another one done again because I may have to get full adult tests done. I need to ask about this.

I say a psychologist is probably better for diagnosis, which in your new update, you said you saw. My first pdoc said that she couldn't diagnose autism, but did believe I have/had it, so I found a psychologist to do one.

I'm in Canada, and I probably could have got diagnosed with ASD through our health plan (OHIP). But I also did it for learning disabilities. When you said your psychologist said something about verbal, they have been referring to non-verbal learning disorder (NVLD). It's quite common for people with Aspergers at least to have NVLD too. Autism and NVLD have some overlapping symptoms.

My sessions were over the span of 2 weeks. I had 3 sessions, each about 2-3 hours long.

For me, this is what happened: I showed up with nothing (well, my clothes, but nothing special). They gave me and my mom a bunch of forms to fill out (my mom since I was under 18). But I have heard adults being diagnosed with a parent interview. Like, the psychologist asked the person's parents questions about their childhood. But anyways, and then I had to do a bunch of tests. You don't need/shouldn't prepare for them. That may ruin the "true" results.

Tests I did included:
Wechsler Adult Intelligence Scale - 4th edition (WAIS-IV)
Wide Range Assessment of Memory and Learning - 2nd edition (WRAML2)
Conners Rating Scales - 3rd edition (Conners-3)
Teast of Everyday Attention for Children (TEA-Ch)
Conners' Continuous Performance Test II (CPT-II)
Behaviour Rating Inventory of Executive Functions - 2nd edition (BRIEF2)
Wisconsin Card Soring Test - 64 (WCST-64)
Delis-Kaplan Executive Function System (D-KEFS)
NEPSY - 2nd edition (NEPSY-II)
Kaufman Test of Educational Achievement - 3 Edition (KTEA-3)
Nelson-Denny Reading Test (N-DRT)
Conners Comprehensive Behaviour Rating Scales (CBRS)
Social Responsiveness Scale - 2nd edition
Behaviour Assessment System for Children - 2nd edition (BASC-2)
Autism Diagnostic Observation Survey (Module 4)

ADOS-4 is probably one of the best, if not the best, for autism out there. It is quite known for being accurate in terms of its diagnosis. I met the criteria for autism spectrum under ADOS.

Oh, and the results took a month to get back. I was quite anxious about it between after the test and the results...

For me, I like that I know because it explains so much about me. I know what to work on. I'm going to be joining an autism spectrum therapy group once it starts running, so hopefully that will be good. For me, I mainly got this assessment for accommodations for school, because I would fail most of my courses if I didn't.

Good luck on your journey.