you're 16 ash, you're no longer a child, this is the time of life when you have the choice to either face adversity, or cower in the corner.
at some point in life we all have to face challenges, it's how we grow into adults.
just because someone doesn't agree with you does not mean they are picking on you or trying to push you down, it is up to you to take in criticism and choose how to face it.
perhaps you can choose to take in a negative reaction and really, REALLY think about why someone disagrees with you, you can logically address it and then see where you stand, not just cry out how unfair the world is.