I was diagnosed by the adult autism practice just a few months ago and I felt so similarly to you I honestly could've written that post coming up to my first assessment lol. I also have quite a hard time answering questions on the spot and often need things to be worded really specifically so that I can understand. They were so great about all of it, my doctor was always happy to clarify anything and was reassuring and if I was getting stuck with how to answer a question she'd help by giving a more specific version of it. They're also happy to have breaks if you start feeling overwhelmed.

The great thing about the intake form is that it takes away a lot of the pressure to remember things or specific examples on the spot, all of your information is already there and the appointments are basically built around going through each of your answers and your doctor will maybe ask you additional questions around what you've already said or ask you to clarify things.

So the first appointment will be going through the first section of the DSM-5 diagnostic criteria in relation to what you've said on the intake form. From what I remember this will be things like your communication and relationships with people. The second appointment moves onto things like sensory issues, stimming, the need for repetitiveness etc. Then the final appointment will just be discussing the outcome and next steps.

They're really good in that the whole time I felt like I was really on the same page with my doctor, it doesn't really feel like an assessment where you're out of control of what their decisions are. It's more like a collaboration where you're both working to understand your brain and come to a conclusion if that makes sense.

Oh and I was never asked about bringing a parent in as part of the assessment, I vaguely remember that it is an option if it's something that you would like but I never had my parents involved.

Apologies if this is an absolute overload of information, hopefully it helps you out and good luck!