You might have executive dysfunction or seasonal depression, or both (like me). Since I went through the same thing at your age I'm not going to suggest that you do what the psychiatrists are telling you will work (because it won't and you know that it won't) but I certainly would advise talking with someone who can offer physical reassurance in response and make you feel relaxed emotionally; for me that person was my mother but I respect that not everyone is lucky enough to have such reassuring parent-figures in their life.
I understand that it can be extremely lonely when you're in that kind of position, but you definitely can't just give up on having social interactions; If you make a habit of actually talking with people you're grouped up with, for example, that little bit of interaction can go a long way towards changing people's perceptions of you. However, the most important thing you can/need to do is to be self-confident, even if it's just as a barrier to protect yourself from yourself.
I have Asperger's Syndrome, I dropped out of school at age 12. I'm now 22 years old and, after working hard for the past 4 years to work my way up through the qualifications ladder, I'm at university studying for a joint-honours degree in Japanese and English in order to fulfil my dream of teaching English in Japan. I have more friends than I know what to do with, I live on my own and have a healthy social life. I defy most every identifying label of Asperger's Syndrome despite how much they affected me when I was in my early teens and yet I retain everything about my Asperger's Syndrome that makes me who I am.
No matter what; I am completely and utterly infallible because I can do exactly what I want to do and succeed at it.
Of course, I recognise that not everyone can be me and that I can't always prescribe the best advice for every individual. However, I do believe that self-confidence is the most powerful thing that people like us can posses.