Feeling so Hurt

Today one of my best friends made me cry. She didnt know she did it but what she did really hurt me. I was on myspace today and i found out she was having a christmas party and didnt tell me. She has a #1 best friend who she has known along time and has told her first, then she told one of my friends who goes to school with my sister and in my mind i'm like, why didnt she tell me? doesnt she want me there? i'm one of her closest friends too.? After hearing that, i went straight to my room and i cried..... i was so hurt. She doesnt tell me anything anymore and lately it just seems to be her and her long time friend. Um why does she have to pick favorites? Why doesnt she treat us all the same? Whats wrong with me? There is a basketball tournament and she didnt even ask me if i wanted to go. I dont think she knows shes one of the big reasons why i'm so unhappy and i'm in tears alot, and if she did know, i dont think she would care. This hasnt been a good day and all i want to do is cry some more.I dont know what i can do to let my friend know how much shes hurting me. She never wants to hang out with me anymore. I'm so confused. What did i do?