Big fights-best friends?

My best friend, Deija, has suddenly stopped talking to me. overnight. and I have no idea what I did to upset her. I tried asking her face to face in a clam, non-judgmental manner, but instead of saying anything, she walked away! I tried texting her and she said 'well i just get p***ed off easily and you found a way to do it. I said 'that's not fair. I don't even know what I did' but she just said 'well, the worlds not fair'. everyone tells me that if she acts like this, she is not worth it. But I really miss her, and I at least want to know what I did. It hurts really bad because half of my family has stopped talking to my close family, so it hit a nerve that she would do the same thing. now she is telling my friends that I'm an awful person and that they should be friends with her, not me, so now I've lost 2 more friends, Makayla and Shari. I am 15 years old, but I honestly don't know what to do! please please please help me!