Friend problems can someone help me ?!?!?

one of my best friends said i was 2 faced she said theat i went to one girl and talked about her then went to her and talked about the other girl but i really didnt i was compeltey honest with her and she flipped on me saying i tought u were a diffeent perosn and all of this stuff and so then she said she doesnt want to be friends with me and know i have a big knot in my stomach and i am crying and i am eating so much wat should i do wat should i say 1 quater of my friends dont like me now when i did nothing she doesnt believe me at all pleas helpp