And so I decided I was an extravert, though it's fairly moderate/low.
Also, try not to confuse being social and confident with being E - we can be shy, too! ^^ Though 'desperately want to go out and be more social' does sound to me like an E who's in the habit of not being social.
A better indicator is more like, if you're with a bunch of people you don't necessarily know well for a long while - at the end of the day, do you feel tired and need some time to yourself, to recoup? Or do you find that you're more energised, and wouldn't mind staying around the people longer?
It probably won't be that clear-cut, but maybe that'll help some?
(Okay, I'm totally giving you conflicting advice. >< I'm sorry! I hope you can make more sense of it, though.)
Don't worry, you'll work your type out eventually. Even if you decide on xSxJ, or something. Plenty of others do.