Stressed and Worried About my Future?

Just feeling stressed a bit, but guess that's how anxiety and depression can work at times. My parents both in their 60's are getting older, and I'm 35, still living at home. Living in California, rent can be high $1,500-2,000 if not higher. I've never lived on my own; always lived at home my whole life, because my parents didn't mind me staying at home. And I am an only child, so they don't mind because I am the only kid. But anyway I am just scared of my future, one of my so called friends, goes and tells me "What would you do IF your parents died tomorrow?" and it had me thinking and now worried. What IF they did what would I do? Yeah they will leave me money and I should be okay but what if that money runs out, and then me working part time I won't be making that much. And I know I could go full time but I don't think I can handle full time hours, 40 hour weeks if not more. That stresses me out too. Then me paying bills and taxes and other stuff, again what if I can't afford it. I know a lot of people prob. think about these sort of things and it is just getting to me a bit. :/