Sounds like me from earlier on in this decade. I'm doing fine now. People just assume I have a degree. The only thing it has hindered is the possibility of me getting an H1B and working in the U.S.. After I dropped out, I was really paranoid about proving myself. I'd hang around on TopCoder and several head hunters on there offered to hook me up with interviews with big companies in the U.S. like Microsoft. It's my understanding I wouldn't be eligible for the required H1B however.

Education matters so long as you're mature enough to make it matter. The vast majority of undergrads from the mid-90s onward coasted through university and didn't learn the fundamental point of it which is to ultimately be able to learn on your own. Having had to interview people with varying levels of education, I can say there's little correlation between success and education. Intelligence perhaps, but at the rate that universities are printing degrees, they've literally been forced to lower their standards. It's my opinion that in general, a university grad of 2009 has undergone a much less rigorous education than that of 1979.

Here's a tip though. You need to seek help. We don't fully understand depression, but it's my opinion that it's the equivalent of your brain's Check Engine Soon light. You can keep driving with that light on, but you'll ignore it at your peril.

I'm speaking from experience here... judging by your statements here I don't think you're in any condition to think about starting a successful company. Take a sabbatical if you can afford to. Get your emotions and relationships figured out, start exercising, sleeping a fairly consistent sleep schedule, and eating healthy food. If you live with your parents, consider taking on a part time job to contribute toward paying expenses. Spend the rest of the time just sampling different experiences. You'll eventually notice a trend and that'll be your path.

And for goodness sakes, keep your social life and don't be afraid to have a few drinks a week. Just don't overdo it. Making yourself a hermit to "be more productive" will backfire. I made that mistake too. Now I just look back at those two or three years in my early 20s like they're a black hole I wish I could fill with actual memories. I stunted my emotional growth and basically spent my late 20s catching up for all those experiences I missed in my early 20s.

After 6 months, revisit your decision to drop out. As someone already mentioned in this thread, closing counts for a lot. But if you decide you'd rather start your own business, you'll have a clear mind and a healthy body to devote to it. Right now, you don't have that and it will undermine your plans.

If you want to chat more about this, let me know. I promised my parents I'd eventually get my degree. I'm not one to break my word, so my current plan is to cash out of my business then go back to school and become a permanent student... one of those annoying mature students that asks a ton of questions in lecture because they really really really are passionate about learning.

EDIT:

One thing to add. I didn't know a bloody thing about running a business when I dropped out. There's no way I can spin that to be a good thing. It was just terrible and I was foolish thinking I could run a successful business when I didn't even know what that meant. I found my legs in business only after I decided to pack it in and take a salaried position with a small company. I eventually left that job but I used that experience to absorb as much as I could about running a business.