I've learn from the past about this situation...
Sometimes people don't know how to comunicate their insatisfactions, keep it inside in front of you but talk about it to the others, and during this you don't understand why everybody is acting weird...
It grows, and it grows and then when you don't expect it, BANG! everybody is mad at you.
Last time it happened to me, I was like : What did I do!!??
They kept doing stuff without me, and suddenly I became the unwanted. My roomate (and friend for 5 years) told me : you know, sometimes we just want to do stuff between us (they were 4!!!), you're my friend, not theirs.
What?
After 4 years hanging out, going to clubs, 2 new years eve, partys and such, I'm not their friend yet?
Yeah right.
I don't need people like you.
I left the appartment, went back to my parent's place, and 6 months after left the city.
They still talk to each other, behind their back too
Don't waste energy on this. You already made your part. If this girl has something against you, the honnest and mature thing to do would be to tell you, try to fix it!