DS1 has a life expectancy of 58 then. And is 9 times more likely to commit suicide
Santas, oh honey, that is NOT the case - nobody knows what life expectancy anybody has!
Statistics are absolutely useless in predicting individual outcomes. I'm no autism expert, but when it comes to, say, cancer being told 'your disease has a 5 year survival rate of 10%' is devastating, but in fact nobody knows whether the person is going to be among the 10% or the 90%.
Average life expectancy of x years includes ALL the v young deaths and those who die at a much older age. A mean life expectancy would be much more interesting IMO.
My DS4(6) was v upset the other day when he heard somewhere that women have a longer life expectance than men because he though that daddy was going to die soon. It was quite hard to explain to him the intricacies of statistics…
There's no denying the horrible health implication for people on the spectrum, both for physical and in particular mental poor health, but look at it as a heads up, not a verdict 
ovenchips, aw shucks, thanks
. One tries. Sometimes in the face of adversity
Queen, if you felt a diagnosis would be helpful to you, do go and ask about it again. Whoever you saw sounds a bit… horrible ignorant. There are other GPs out there, honest.
I think the perception that it is a 'children's disease' or condition is due to the lack of available support for adults with ASD. I think it is vitally important that children get diagnosed as soon as possible in order to get support in at school and at home etc. High functioning adults with autism will be seen as less of a priority because they are, well, 'high functioning'. At what cost that high level of going about their business in the Real World comes is not part of the consideration 
If you think having a diagnosis (or indeed being told that you don't meet the criteria) would help you either simply as an explanation for your difficulties or on a practical level, don't be put off pursuing it again.
I often lurk on the SN/Neurodiversity threads and I tellya, it is an education 