I'm 21 and was diagnosed a couple months ago.
The circumstances were a bit different for me since I didn't come in with a self-diagnosis. I started seeing a therapist for help with social issues, and it led to a diagnosis. He suspected I had AS from the second appointment, but didn't make an official diagnosis until the 4th appointment. The first few sessions were basically getting inside my head, pointing me to some AS/autism resources, and helping me reconcile myself with the diagnosis (in retrospect, I definitely went/am going through the stages of grieving, to a lesser extent).
_________________
musingsramblingsandmore.blogspot.com