Frumpet you sound like my sis too kind and too helpful. She would go knocking retail units with him too for a weekend job. It doesn't help he doesn't look independent and confident.
He sounds just like my nephew say he has to get his own flat, after a week of that he'll be begging to come back home and sort himself out, or he will actually sort himself out and stay put in own flat.
We have a saying in my culture there will come a time when children will become the masters of their parents. This time is now.
my parents generation would take all kids earnings from weekend jobs. I didn't agree with that. But now I agree partially and adult child living with you should have a job part time if studying full time if not, and they should pay something towards up keep, so they realise the worth of money. today a lot of older kids live with parents don't lift a finger and don't pay a penny towards anything, makes for selfish human beings.
I speak from experience none of my siblings are caring for my dad yet they live in his home rent free bill free , and they are fully grown men. Youngest is your sons age. I can't take him I've got in law, can't deal with another dimentia patient unless she is taken by another family member.
I won't be that parent I'll kick my child out first, if it means it knocks some sense into them. Don't be a doormat.
I hope he gets work soon and looks hard for one. Good luck!