What should i do im in a fight with my friends??

Heres the behind story; The day before the scirnce fair i was taking to deanna [best friend] and tatiana [friend] and i told deanna that i would ask my mom if i could take her to the movies. Next day; After the science fair me deanna and tatiana were talking. i left, and tatiana made plans with deanna to see alice in wonder land and they went yesterday. And yesterday tatiana whispered to deanna and ditched us. She 's gonna rub it in my face now because she went to the movies with MY BFFFFF {me and deanna are practically long lost sisters}