What to expect at an adult assessment for ASD

Hi all,

I'm completely new to this community and was wondering if you could help me?

I am a 23 year old female who has been finally referred for an assessment for diagnosis. 

I'm sure you're all aware of how difficult this can be, being a girl and every single medical professional never taking you or your parents seriously and so on because you outwardly appear 'normal' whatever that is. 

I was diagnosed with an unspecified developmental disorder as a child because they didn't have enough evidence to say I had ASD (or perhaps because I lied a lot to avoid a diagnosis because I didn't want any more bullying or people to think I was weird) it's tough being a teenager!

since my referral I've been browsing this online community and other sites and I can resonate with a lot of the things people are posting and talking about. I too often find myself overwhelmed by sounds and lights as if the world is a living, spinning kaleidoscope. I love animals, they're all I want to talk about and I have loved collecting facts about them for as long as I can remember  

anyway my question is...

What should I expect at an adult assessment for ASD?

what questions do they ask/how long does it take/is it really awkward/frightening

i am really nervous even thinking about it, thank  you