Well I'm 30, I do not live with my parents, and I've never had a job. From about 19 to 25 I lived with my sister and babysat my nephews for her while she and her husband worked. It made me feel like I was at least useful in some way. After that their situation changed and they didn't need my help anymore. I've since been splitting a 2 bedroom apartment with a room mate. Like tehuti88 above I'm on SSI for my SA, which is how I'm able to pay for my half of the bills.
I often feel a lot of shame about the fact I've never had a job. It makes me feel like a worthless, useless person. I'm working on improving myself and my SA, but even if/when I do get better, I'm not sure if I'll ever be able to get a job. I have no degree of any kind, and even minimum wage jobs will be leery of a 30+ year old with no job history. Not to mention many minimum wage jobs involve dealing with lots of people(waiting tables, cashier at a store etc.) which would be exactly the most difficult kind of job for me to face with my SA.
I really wish I had any useful advice to give you, but I don't.