My DD has managed to get a part time job in a well known fast food place. I did not think she would manage too well (think meltdowns when things don't go her way etc), but she surprised me ! 
She was always very confrontational at home but the model of best behaviour and maximum effort at school (every report card said very well behaved, excellent effort in classroom and for homework
), but no effort at home and lots of screaming meltdowns, total refusal to either listen or comply with requests etc
.
I know kids on the spectrum usually keep their worst behaviour for EITHER school or home, and we got the worst at home, but it meant she did well in school.
I don't know if your area has any special places that employ ASD people ? In my area there's a few places that employ the more severe cases (some make furniture, and some work in garden centre type places) and a few others like supermarkets etc that actually look for people with milder disabilities to employ ? It's maybe worth asking around in places that you think your DC might enjoy ?
Are there any clubs etc near you that would be suitable ? I found out about local clubs etc when my DD was younger and we attended quite a few. It's from them that I found out about other clubs etc ( there was one here called 'social eyes' which was specifically for older teens and young 20's with milder ASD to meet and make friends).
My DD also attended rainbows, brownies etc which helped her enormously with socialisation etc, so maybe your DC could find something they would like to volunteer at first ? Maybe even volunteer in a charity shop to see how that went ?
Also, my DD is obsessed with horse riding and is going to do equine studies at uni, has your DC got a particular interest that they could study further ? I found out lots of areas my DD might have studied e.g hairdressing ( she prepares the horses for dressage competitions and does it so well that adults at her stable have been paying her to prepare their horses too for a few years), stage make up/ lighting etc (she did A level music and drama and is brilliant at both), acting (she did advanced A level music using voice as her instrument :)) etc.
Whatever she was interested in and was good at, I investigated, no matter what it was, and encouraged her by saying ' Oooh, did you know there's a course in that at ......college/ uni ? just to put the idea in her head.
Can you think of anything like that for your son ?
No, I don't think you're negative at all, just a normal worried mum, same as me :)