Problem in school, what should i do?

Okay, i am in highschool. There's ths girl in school [my ex bestfrnd] her name is elena. Well, we used to be lke sisters, we wre inseperable!!! Idkk wht happened but all of a sudden she stopped tlking to me! Thre was rumors tht it was becausee she was jealous tht i tlkedd to her boyfrnd [hector] so thts why she stopped tlking to me, so tht he wnt tlk to me either!! Later i heard tht she was telling ppl tht she wasnt tlking to me becausee smeone tld her i lke hector!!!!!! and tht is so NOT true! I love my boyfrnd and i never lked hector mre thn a frnd!! I txted her and tld her tht i dnt lke her boyfrnd and she wnt off telling me sht! I got so pissed off and tld her sht bckk. Ever since thn, she doesn't shut her fckinn mouth!!!!! She is seriously pissing me off! I would fight her but i dnt wnt to get my hnds dirty and even if i wntedd to i cnt! I already got into 2 fights in 1 semester which means tht if i get into another one, i will be expelled. I cnt afford to be expelled becausee tht will jess ruin my education! I go to an early college high school so it will ruin a lot for me!!! I dnt wnt her thinking i am a or i am scared of her because i am NOT!!! Wht shld i do????!!