It's not so easy to make these big decisions especially considering the current job climate. Given the economy et al, it's really not your 'fault'. Think more about what you can learn from the experience.

You said "it must be me that's the problem"... I don't know if that's true. Maybe you should think back a little bit. What were the warning signs you saw in the interview? How did you react? What questions could you have asked that could have helped you get a better sense of the job? And, were there any actions you could have taken to avoid this situation in the first place?

Remember not all this is your fault, but YOUR actions are the only ones you can change or have any control over. You can't change the fact that jobs are hard to get, etc. But you can learn from your experience and maybe end up with abetter experience next time?

wishing you luck