Hey
I'm only young too (19) and these should be the happiest years of my life... going out with friends, having a laugh and making a fool of myself. But, unfortunately we're in a similar boat I guess.
I'm really depressed and even having a very loving and supporting boyfriend I'm still not happy (doesn't help that he's 270 miles away at university though).

Have you spoken to any councillors/therapists... or are you on any meds?
I've put my foot down on meds... I will not let anyone put me on them again after a bad experience. Plus, I KNOW i can pull myself out of this once I build my confidence up and talk to people my age and once my 'illness' is sorted.
But, sounds to me like that may help you.
Go back to your doc maybe, if you haven't already and explain how you feel. I know some therapists don't help, but you've got to push until you see someone that does.

Best of luck,
molly