I've been in a similar situation. Working for 4 years in dead end jobs, not knowing what I actually want to be for the rest of my life and worrying myself silly.
I feel better now as next year I'm travelling to Canada for the year to basically have the time of my life. I agree whole heartedly with the others when they say you should travel.
Other than that, do you have any hobbies or interests? You'd be surprised by the sort of jobs people end up with just by following their passions!
Sorry if its not much help, but definitely do the travelling thing, good luck!
Anna x