I feel I have ruined my life by worrying. As a child I worried about my parents! My kids are grown up now but I still worry.
I think all you can do is offer practical support. My son lives in Australia now and has a good life, but when he was out of work and house sharing when he lived in England I used to make sure he ate by taking round bags of goodies and helping him out by giving him lifts to interview etc. It dosn't stop the worrying, but at least you feel you are helping in some way.
Think back to when you were his age Langfordlady.....which I what I tend to do now. You were an adult and part of being an adult is finding your own way, dealing with disappointment and so on, we all had to do it. Just be there for him, invite him round for meals, be his 'shoulder'. He will find something in the end I'm sure.
My son's main problem was staying out all night and sometimes for nights on the trot when he lived at home. He would go out on Friday night to a club and wouldn't turn up until Sunday, after spending a weekend at someone's place . This used to scare the life out of me, as he would 'forget' to text me. He was a real party animal and I would lie awake, sick with worry. Now he's in Australia he is settled and happy so I do not have that horrible sick feeling any more.
My daughter is married with her own family and I still worry about her - if she goes out with her friends for a night for example, and there are also 3 grand-children for me to worry about.
Sometimes you just have to go with it, ride the storm as best you can - I think that worrying is in some people's DNA, it certainly is in mine.