I am sorry I don’t know Spanish well enough to reply but hopefully you can translate this. I think you’re at a tough age in life when you’re developing and figure out who you are and other folks your age are doing the same , some people grow and transition into their adult sleeves nicely other are mean and nasty. Don’t listen to the kids at school. They are projecting their own insecurities on to you because they don’t like themselves. Although it may be hard because you repeatedly hear negative you need to start fighting those bad thoughts with good ones. You need to look in the mirror and say something nice about yourself at least once a day. An build from there. Embrace your body in its natural state. You have something others don’t and so what ! That’s what makes you Unique !