how to help my son accept he is autistic and ask for help

We mature different. Society does not tailor it's education system to suit how we learn and grow. Gen X'rs dealt with this by calling themselves "Late bloomers", when in fact, had we learned fundamentals principles of things in a natural order rather than chaotic and social, we would be ready to learn some social graces as a conscious and formal means of exchange in our late teens and worked toward adult things in our 20s. Society has never existed like it does now. By 18 we're expected to have a specific career trajectory, with a entrepreneurial outlook, the playbook on power, social forms and mannerisms, opening portfolios and getting a drivers license. 

But autistics being thrust in to a whole system we're mismatched for, are exhausted by 16 and giving up. So, sounds about right. The system makes me a bit angry and I personally want to influence change. 

It's amazing you're allowing him to grow to the next step when ready. I'm not sure I have practical advice, but any critical thought you can encourage is will help him succeed.  Anything you can do to help expose him to ideas and opportunities, is important. We all have multiple things we might be good at but in order to get there, these talents need to be seen and 'drawn' or called out. However, nothing can be more supportive than family, allowing room to grow at ones pace if they can, helping with recourses and minding general health and well-being. 

We mature different. Society does not tailor it's education system to suit how we learn and grow. Gen X'rs dealt with this by calling themselves "Late bloomers", when in fact, had we learned fundamentals principles of things in a natural order rather than chaotic and social, we would be ready to learn some social graces as a conscious and formal means of exchange in our late teens and worked toward adult things in our 20s. Society has never existed like it does now. By 18 we're expected to have a specific career trajectory, with a entrepreneurial outlook, the playbook on power, social forms and mannerisms, opening portfolios and getting a drivers license. 

But autistics being thrust in to a whole system we're mismatched for, are exhausted by 16 and giving up. So, sounds about right. The system makes me a bit angry and I personally want to influence change. 

It's amazing you're allowing him to grow to the next step when ready. I'm not sure I have practical advice, but any critical thought you can encourage is will help him succeed.  Anything you can do to help expose him to ideas and opportunities, is important. We all have multiple things we might be good at but in order to get there, these talents need to be seen and 'drawn' or called out. However, nothing can be more supportive than family, allowing room to grow at ones pace if they can, helping with recourses and minding general health and well-being. 

Too much Schooling, and not enough Learning.

The Education system is too dependent on rote learning, for an exam. It puts kids under too much pressure. Previous generations, who left school at 15 and did apprenticeships, matured far quicker; as they had a sense of direction. Nowadays, our Nation has a culture of dependency, and entitlement.

My Generation were the Guinea Pigs for Millennials. We thought that, by listening to Oasis, we would become movers and shakers. But, up popped the Spice Girls. Then everything went AWOL.

My brother was in the same situation, until he joined an employability group. That helped him become a stable young man. Now, he is doing his own Software Development Project; so top-secret, I'm not told much detail. However, I don't interfere in his life anymore.