I want a healthy diet but i have a eating disorder of only eating chips any ideas of helping with my problem ?

Hi i am 13 years old and i weight about 12/13 stone which is verry over weight for a girl my age now i would like to loose weight but its not all about the exercises. I can do all exercises but i currently have a eating disorder where i only eat chips and toast everyday 7 days a week i eat other stuff but its them everyday my other stuff are busicuit and chrisps i dont no why i dont like meat or veg i have never tried them i guess i am scared silly ino but if i keep eating like this ill be as big as a sumo wrestler any ideas of how i can confront my problem because i want to loose weight before its too late . thanks :) I also drink 2 litres of coca cola a day i am addicted to it please help x