(((((((((((MUE))))))))))))))
I am in such a similar situation with my former best friend. She was always nice to me, but SO judgmental/mean about/to others, and when I finally stood up for someone, she dumped me in a BIG way. And did just what your "friend" is doing...made it REALLY obvious in front of me how bonded she is with other people, how many inside jokes they have, how much fun I'm missing. Ack.
I go through moments of acceptance, like TOTAL acceptance, and then moments of panic. She actually didn't talk to me at ALL for a while, but just responded to something I posted on FB, so maybe she'll at least be cordial. We're both homeschoolers with basically the same circle of friends, so it's inevitable that we'll be together a lot.
I *knew* somewhere deep inside for a while that it wasn't a healthy friendship for me...but it's so hard to let something like that go, because there are always good times too, you know? I finally realized that there *are* nice people around me, and I started reaching out more to them...and slowly, but surely, these NICE people are the people I'm spending more and more time with. And there's no drama...just honesty and laughter and support...and it's really nice. I'm not tense all the time waiting for the other shoe to drop.
My T told me early in therapy that as I changed, things would change around me. Sometimes it's scary and painful, but I try to hang onto the hope that I'm making space for something better.
You did the right thing, MUE. Breathe, and know that YOU are okay.

