Congratulations on the diagnosis! You haven't let anyone down, and from here you can only understand yourself and how to deal with any problems you have better!
For all those looking for a diagnosis in the UK, the legislation call the Autism Act 2009 was a big milestone in Autism law and has more information on it here http://en.wikipedia....Autism_Act_2009
It is meant to push the government, health service and local trusts to have in place a clear pathway for diagnosis for all(not just children, this focuses on adults) and the start of training and provision of services for those with ASD. In practice all of these things are still four years on relatively thin on the ground, especially dependent on the area you live.
The first step is contacting your GP. Go in with a list of symptoms after doing your own research, and also a list of difficulties you face. Detailing problems with socialising, interpersonal relationships and especially finding and holding work are really the things that will make the best case. Ask for a diagnosis from a someone who knows more and get them to clearly explain what will happen next.
then be referred to your local Primary Care Trust or PCT, which is really more about mental health, who may hold a meeting to determine your issues and needs, or a clinical psychologist who may be able to diagnose with the right expertise, or best of all a specialist local service which may or may not be government funded. The waiting list for a diagnosis, let alone help, may be long.
If you are not happy with your doctor or feel you have not been taken seriously or brushed off, make another appointment with a different doctor or surgery, you are completely within your rights to do so.
In the case that your area is not best equipped to help or there is a large waiting list, there may be a case for you to be sent to a different authority outside your area if funding is made possible. You can discuss this ith your doctor, but I would suggest using the National Autistic Society's Services Directory looking for diagnosis and support in your area here http://www.autism.or.../directory.aspx
Also e-mail the NAS or even join them! They are incredibly helpful and I could not recommend anyone more.
Pappy - Congratulations again, you've got further than many others have (including myself, now over a year waiting for an official diagnosis) and get reading on the subject, meet some others and keep posting if you ever need help