http://en.wikipedia.org/wiki/Impostor_syndrome
But my story is a different topic. Some quick advice:
(1) You already know you're headed towards a brick wall. The most sensible thing you can do at the moment is to soften the blow, and buy yourself time. Really, every $50 or $100 is critical here... so if at all possible, pare down your lifestyle to the barest essentials.
An apartment lease (in SF!) is probably the easiest to dispose of, and will net you the most cash, especially if, say, you have friends in the East Bay (or practically anywhere else besides the city and its immediate suburbs) that you can talk into letting you move in without a deposit. Plus you'll get your security back. That change alone might help you coast until Dec or Jan.
(2) after that, you need to put yourself on an austerity budget, i.e. you should be able to get by on $5 a day or less on food from grocery stores, +perhaps $2.50 a day if you must use coffeeshops for wifi. If you can avoid using public transit save for special trips, that's a huge plus.
(3) -DRASTICALLY- lower your expectations for you next job. Customer support, friggen PHP dev... whatever it takes. If you don't get tech work, just work at a Trader Joes, do delivery work, ANYTHING. Bottom line is it's VERY important to get out of the idea that you have to borrow money from people unless you're truly, seriously on the edge... which it sounds like you aren't6 yet, not by a longshot.
(4) finally -- you're in yout 20s (sounds like).. you're touhgh, you can take anything. forget about what other people think and their so-called "success" stories. just concentrate on you'r own story for now. Trust me, when you pull yourself out of this (and you will) you'll have a lot to be proud of + to look back on yourself positively for.