Is it normal that i'm sick and tired of my "best" friend?

I have a question about a 'friend' (we're both girls). We used to be really close in high-school; her personality was open and she helped me become more comfortable to speak my mind. But she's extremely loud, very self-centered (always complaining about her problems, upset when things don't go her way, jealous of me when I am together with other friends or a boy). She was always like this, but I somehow never minded before.

But now we've graduated. And I think I've changed or something, because I started to dislike those qualities more and more. So I avoided her for most of the summer. Recently we went to a festival together, just us two and we met up with my other friends during the day. I got together with a guy friend when I was quite drunk and we made out. My friend then got all pissed and called me a slut (I'm still a virgin) and then had a fight with me later on about how I never ask her what she wants and how I'm ditching her for guys. She's done this before, always guilt-tripping me when I have a little bit a fun. And I actually do consider her welfare and look after her when she's tipsy or having her period. But she's just never content if I am; she always wants things to be around her. And it's also ironic how she calls me a slut all the time, yet she dies her hair blonde and styles it in a hot bombshell way and talks in a really horny voice, especially when there are guys around. I never judge her when she does this... yet she judges me completely.

Now we're back home. She added all my friends that we met at the festival on facebook. She comments on all their photos and walls, and i'm beginning to feel like they're getting annoyed. At the festival when we were with my friends, she kept making really snobby comments like "omg that guy burped in my ear!!" or "everything is so nasty" (come on, its a festival). I even saw one of my friends give another one a look. So the fact that she's commenting on all their stuff on facebook is really quite embarrassing for me. I don't want my friends to judge me because of my association with her.

She hasn't commented anything on my facebook. Plus, she uploaded a facebook photo of us together and she cropped me out, in a very obvious way. I know you may roll your eyes about all this facebook-insignificance, but I feel like it's at least a little relevant.

After this long rant, I just want to know -- What is up with this 'friendship'? Should I accept we're different people and break it off? I'm leaving for university in some weeks and she's staying here at a not-so-good local university.
Or is this my problem and I'm really ignoring her?
Thank you so much in advance for the help!