My mom won't support my choice to go vegetarian.?

I understand what your going through! I was the same age when i first became vegetarian and my dad tried to stop me too. Eventually, if you stick with your decision your parents will have to just accept it (mine did though they still aren't happy) It might help your parents to see your that decision is mature and well thought out if you plan out healthy balanced meals and prepare them yourself. To make up for the protiens in meat you should eat lots of beans and tofu. You can find iron supplement pills at most whole foods stores which you should start taking. soy milk has most of the nutrients that cow milk has but the way it tastes might be hard to get used to. good luck!:)