As a child and teen, I was often bullied. A short, fat, nerd makes for a large target (no pun intended).
1) Don't let them see that they are "getting you." The delight bullies get is not from the torment, but the response.
2) Find your center, gather your strength and smile ever so sweetly and with a hint of condescension. Respond to the data in the stream, not the tone or the precise word choices.
3) Always remember the tormentors are the ones whose mind and spirit are poisoned. They deserve our sympathy and pity, they are not worth wasting the energy of anger.
That last bit is the one that took me till very recently to discover and incorporate into my mind and spirit.
The process of discovering these was not easy.
e1 can easily turn you into a emotionless zombie.
e2 requires lots of strength and self control.
e3 is the toughest, because it requires you to give something to the tormentors.