I totally agree with Nelson. One has a much better chance of being a rock star than a professional bodybuilder.
Follow your dreams... but be realistic. There comes a point when everyone must grow up and realize there are natural and statistical limits to what one can do in life. (You won't be a pro bodybuilder. You won't be the president. You won't fly to the moon. Sorry.) You should try focusing on something more productive -- and less potentially harmful -- when you look to your future. Like, work on getting into med school or something else a bit more realistic and beneficial to your future instead of starting illegal drug use at an early age...