hey your not alone,,I'm going thru the same thing as u are right now,my best friend is been ignoring me for the fast few weeks,,shes the one i need right now in my life more then anything,,but try talking to her and sending her text msg's tell her y shes mad and whats the reason she's been ignoring you,,maybe one of your friend told her something or she heared something like you said that somebody told her and thats not true,so try to see her or text or call her and have a convo with her.i hope this helps!
You might have wronged or offended her without knowing it. You should talk to her and determine why she doesn't care about you anymore. Tell her why the relationship is important to you and why you want her to care about you.
As people grow & mature they change(not always for the best) & they make new friends & acquaintances. There's probably not a lot you can do but let it go & find a new best friend. It hurts when you lose someone but doesn't sound like this person is worth your time. Friendship is based on trust,loyalty & equality & it sounds like all that is gone. Sorry, good luck.
Sad way to end the relationship, but it sounds like she needed to grow-up and talk about it instead of acting like you don't exist. Some people don't know the proper way to communicate. Sorry this happened. It's best to move on,you deserve a real friend.