sometimes you can have a lot of friends, but still feel alone; maybe you don't have the kind of close friends where you feel validated; also, maybe you're searching for something that your friends can't help you find.
I'd say it's because you're smarter than them.
being a teenager sucks. some of this is just because you're young... I know you might resent that answer, but it's just true.<br />
The only thing you can really do is try to focus on others, on helping them or being the best person you can be. Sometimes just a shift in orientation (away from your own stuff and towards helping someone else) can make problems seem so much smaller.