I dont know what is going on ?

Can you join any clubs? This would force you to talk to people and for those people to talk to you and you could create a whole new social circle. If this isn't an option, you need to try to go out of your comfort zone and talk to people. The real problem is you created a pattern for yourself and it's easier, at least in the short term, to go through the day and not changing that pattern. In the long run, it's either causing or worsening your depression. I'm not totally against the switching school idea, but I'd suggest only considering that if you've tried to fix things in your present environment. I still think the club/group idea could be useful, but am not sure if that is even an option in your school. As for the depression, being isolated in this way could def cause it, so hopefully if you fix this issue, the depression will resolve. Does this help at all??