Who is the wrong person in this friendship?

Okay, so my friend and I, I guess are going through a phase, and she keeps bugging me about fixing it. So, I get mad that she is talking to people she doesn't even like and I say that she is really fake. Such as we were at our lunch table and she was talking to this girl, when the girls other friend called her over she left for like two minutes and my friend is telling this girl at our table how she's not even that pretty and junk and how they can get as much boys just like her. When she's back she's talking to her like she's her best friend and it really pisses me off. Then I just switch tables because she's talking to all these people she doesn't like and bringing drama to me about her issues with them. I already have enough stress with exams, and I didn't have time for it. She needs everything revolved around her. Now she's telling my other friend the only other one I talk to how I'm not even talking to her and hanging out with her a lot. We tried working it out but she's making it worst? I'm I just taking it over the top or is she the wrong person. And any advice will help to.