Remember that when you are depressed, everything always seems hopeless and there seems to be no way out - but that is all in your mind, because of bad chemicals. You need to speak to your psychiatrist about these feelings, because they are irrational and you should be properly medicated for them.
Another thing, there is always hope.
You say that you don't know how you can ever work because you don't want to deal with other people? Well, there are many jobs in the world that require only minimal contact with others - so don't give up hope yet, I'm sure you will find a job which you might even enjoy - IT sounds like a great direction to head in for you.
The most important thing is to get through your last years of school by any means necessary, and try to get the best marks you can, then after that you can go to uni and study only what you've interested in (IT maybe? Or computer game creation?) in an environment where you have more control over how social you have to be (school is by far the most forcibly social environment). I have a very close friend who studies IT at uni, and pretty much does all his work from his room; he gets his lecture slides off the net, and does readings.
At any rate, school is the worst of it because you are forced to stay in a social environment for long stretches of time, and also to study things you aren't interested in. After school, you are given more control to determine your own lifestyle.
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Into the dark...