You've had a lot of advice for your health problems so I have some suggestions for the other aspects of your life. Your parents have been very generous and understanding, possibly too much so. I think you should watch the TV show Princess and ask yourself if that's you (it's a reality show about people who live off their parents). If your health problems are chronic you probably need to figure out how to earn a living despite them, and if you're not sleeping you certainly have the time to do something that will generate income, even if it isn't something you really want to do. Just make sure you're not asking anyone for help to "get you started" as you've obviously done a lot of that already.
This may sound harsh but it sounds like you have not adjusted to being an adult and at 25 and up it's not going to get any easier.I think you need to work around your health issues and learn to "suck it up" a bit or you'll be in your parents house trying to convince them to let you sleep on the sofa when you're 35/45/etc. Everyone has health/personality/skill/aptitude issues that they have to work around. Earn some money and find a job so you can move to somewhere with a climate that suits you more (I know climate makes a big difference for me), but this time do it on your own and make it stick.