Sorenna, I'm 49 now and didn't even know what Asperger Syndrome or HFA were until I was 45. When I was a kid, you were either ret*d (stupid) or you were normal and that was it. There were no other allowances for being different. Lived my whole life without knowing that the oddness about me was anything other than me being eccentric and unable to fit into mainstream society. I and those around me assumed it was a personal weakness of character only slightly balanced out by a high IQ.
While it's nice to know that there is a biological reason for why I am unique among my peers (at least it doesn't seem like a personal flaw anymore), and it's gratifying to see that I'm not alone in feeling alien to NT society, it doesn't change anything really. I still face the same challenges and still have the same opportunities such as they are.
Have I 'lost time' from my life because I didn't know about AS earlier? Mmmm...maybe...but all things considered, I'm not sure I'd have done anything differently either way. So for all practical purposes, no. Knowing hasn't changed my difficulties with social interaction, or the sensory overstimulation that goes along with it. It affects the jobs I'm able to accept tremendously, in ways those around me can't begin to comprehend, but hey, everybody's got their problems.
I understand the feelings of hopelessness, I struggle with that in cycles as I think most of us here do - thought I wasn't going to survive a bout with S.A.D. this past winter - but you can't live your life angry and depressed all the time. AS is certainly a handicap, a disability, but at least it's not terminal (unless we give in to that depression). We have just as much right and opportunity for happiness as any NT does, AS just limits our choices a bit. And keep in mind, there are plenty of people not on the autism spectrum who are also not neurotypical, and they get through their lives somehow, too.
Be glad every morning that you have fingers instead of flippers and your tail doesn't hang out of your pants. If it does, pull up your pants.