Remember when someone says something like that to you, it is to make you feel sad, bad about yourself, scared and miserable. Don't catch their ball. Its like a game, they throw the ball and you catch it by reacting the way they want you to, so don't. Just shrug and say "whatever" and move on. You can't control idiots and bullies but you can control how you react to them. Try it and see how you get on.
Life is too short to waste time dealing with morons who play these stupid games, so don't play the game.
I would also consider letting the staff at the school know you are being harassed and bullied by this idiot. It's their job to look after you and deal with this. Hope this helps Gracie. x
Definitely go to your school guidance counselor and tell them.
My child's school takes things very seriously. I am sure yours will, too.
Also, just remember that no matter how old you are, there will always be people out there who will choose to be cruel rather than kind. What matters most is how you respond and how you treat others. Hold your head high and know that you are a valuable human being with much love to give the world. As long as you keep that in your mind and heart, you will feel grounded regardless of what others say to you or about you.
I hope this helps!