Nope, doesn't sound like BDD.
Sadly, what you feel is common in adolescence, especially in hostile school environments. I really hope you get to feel better. Just hang in there. It will take time, but it gets better. I know it's a little difficult, but try to focus on who you are, and don't worry about what other people think of you. Take care of yourself and be strong!
Other than that, disorders are not something to be taken lightly, and they make people's lives really difficult and insufferable, so please don't hope you have any disorder, because they're hell.
@Patrick, Body Dysmorphic Disorder has nothing to do with weight, it has to do with the way one views their body. The area of concern could be anything, e.g. nose, hair, a mole or whatever. Weight-related disorders are usually eating disorders, such as compulsive overeating, for example.