I need help cuz therez an hoo needz 2 be stoppeeed!!?

There's this guy in my skewl and we were like best friends for a while but then he changed.He started 2 lie ALOT and we started hating each otheer after a while I forgave him but the next damn day he lied 2 my other fwiendz about me and itz a reely bad lie and now peeple r guna hate me but i reely didnt do anytin so what shud i do plz help me