I need advice?

im a year 7 girl and all my friends hav bfs but no one likes me cause im really tall and im a litlle big around the waist. i also hav pretty broad shoulders but my face is alright! evryone calls me a teachers pet but when i ask them y they dont know. it is really imature i no.and its a really bitchy year. i care too much about wat other peeple think but i cant help it i always thin they are whispering about me! im really good at good comebaks wen im by myself but wen im put on the spot my face gos brite red and my mind goes blank. pleese help me wiv advice.