Hi Johnk,
For me, getting diagnosed as an adult was worth it.
There is no "cure" or therapy or medication as such - but there are various things that help various people with some problematic aspect of Aspergers. Quite a few people here would suggest regular visits to a psychologist who specialises in Aspergers, who can help with getting through life successfully as an Aspie. I've also had biofeedback suggested, but don't know enough about it to discuss it. And there are common problems that go along with Aspergers, like depression or OCD, that can be helped.
For me, the most important thing was just to know there was a reason I am the way I am, that I'm not just weird or defective, I couldn't be different if I just "tried harder" - it's about recognition that there is actually a problem. Imagine going through life vision- or hearing-impaired, and being told "you could see/hear if you would only try!" That's the line I was being spun when I screwed up socially because I can't process body language or social cues, couldn't park a car because my spatial skills are poor, or any of the other common Aspie dilemmas.
I can relate to your psychiatrist experience. I've seen three GPS, two psychologists and three counsellors in recent years due to mental health problems, and only the third psychologist picked up my Aspergers. That's partially my fault - there were things I knew weren't normal, like pacing and these endless streams of repetitive thoughts, so I kept quiet about them so I didn't end up in a padded cell. When I finally DID talk about them, because they were getting so damn annoying, Aspergers came up about five minutes into the consultation.
We adult Aspies have often learned enough to be able to function in normal society and mask some of the tell-tale signs. Like, I've never bored anyone's pants off with a discussion of my obsessions. I know I'm unlikely to find another human being who wants to talk at length about Harpo Marx or papier mache, so I just keep my mouth shut.
Goodness, I've written an essay here... but the point was yes, from my experience, it is worth finding out one way or the other.