First, you're at the age when this sort of disorder, if you have it, manifests itself. Second, nobody ever feels depressed for a reason -- people feel sad for a reason, not depressed. It's a ridiculous disease, as is anxiety, which it sounds like you have some of as well. They do nothing for us. If you truly feel this is depression and not just a bad mood that will pass, you might think about finding a psychologist for help.