Getting really tired of it.

My supposed "best friend" is such a bitch to me.. she picks on my insecurities and honestly I'm very tired of it. There's this one time I was shopping for cook books and she told me I should get the diet cook book and lose weight😐 then yesterday I show her a picture of my sister and she says oh she has perfect teeth, what happened to yours😢. I just don't know anymore honestly. What do you think?