You sound like you have the body that girls crave and would kill for (I certainly would)! Don't lose it by throwing up, just keep being healthy and exercising. I see nothing wrong with you.
Please don't throw up for other people. Pleasing them will only hurt you, who cares about their wrong opinions! It is unhealthy, damages your teeth, stomach and metabolism, gives you dark circles, weak hair, wrinkles..... Please don't do it, stay beautiful hon!
As for your family talk to them, tell them to stop bullying you. Bullying from your own flesh, how horrible. Please tell them. If they do not talk to someone at school about it, they are abusing you! I don't know if they're doing it out of spite or if they think they're just joking around, but it needs to stop. Talk to them today x