Girls really are terrible.
I lucked out and made some good female friends when I was a teenager and I don't know what I'd do without them. Two of them are there in that pic in my sig - the girl on the end there with the blue lips might as well be my sister, and the green lips girl and I suffered through many a Paula Abdul dance/workout video together in gym class. We were (okay, we still are) much more interested in comic books and horror films and video games than the drah-mah so common amongst high school kids, so there was never any of that weird fighting or backstabbing that chicks do between us.
But even though I chose not to engage in that type of thing, I did observe other more casual female acquaintances harass and torture each other mercilessly under the guise of friendship, and I also had one or two of those casual acquaintances try to do a number on me a few times - it just didn't hurt much because I never expected those girls to treat me well, since I didn't consider them actual friends.
Guys are way easier - they punch each other and get it over with and are fine again the next day. Girls have loooooong memories.
My daughter is turning 7 in a couple of weeks, and I can't say I'm looking forward to seeing what it will be like when that stuff starts kicking in for her.
But you, Rhiya, are a smart cookie, and you are dealing with this just fine.
PS - Agree about having the best guyfriend. I had one of those, too - we called him Angus (yes, because of that movie. He's outgrown the nickname now, though).