Social Security is not just to those that are 65. You can get Social Security disability at any age. Disability does not require you to pay into it.
Seriously, don't worry about not landing the Amazon gig. They're not a good environment for the majority of us. The only reason they get away with it is because they're huge and look good on a resume because of it. It's a good thing if it never worked out for you, I assure you. In fact, I'd say the same for just about every Silicon Valley company (and I've been recruited by three now, including Amazon). Nearly all of them encourage work cultures that are by and large destructive to their employees, and the average turnover rate is a testament to the poor environment.
That said, you are very pessimisstic. If you are coming off that way in interviews, then it might be what's hindering you. I know it seems hopeless at this point, but if that comes across to others (even as the "vibe" that you picked up from others), then they're not going to want that negativity in their environment.
Also, remember that you have to start somewhere. It sounds like you're looking at tech positions and might be overlooking "foot in the door" positions at the same company. For example, you can't expect to get hired as a server administrator if you have no experience. However, you can start on the help desk and work your way up from there. Yeah, help desk sucks, but you can work with the goal of getting that admin role and get promoted as soon as you can.
Another option is to forego working for others altogether. Start a blog that you can monetize. Self-publish a book on places like Gumroad or Leanpub. Check out the Smart Passive Income podcast and blog for ideas and information on how to do it.
Finally, get help. Why are you afraid of antidepressants? Give them a try, with the help of a good therapist and/or doctor. They very well might be the difference between you being successful and not.