How to stop a lying,two-faced best friend?

We have been Друзья for three years but after I spent some days at her house she started copying me,and trying to be superior to me,shes in the lower class(walmart clothes,layaway) but still says she has a big house and has all this stuff bt its I have еще than she does.She lies about the simplest things (Clothes,house,mother,father,etc.) Her mom is a little bit mean to her bt one time me and my best friend got into a huge fight and she pushed me so I decied to beat her up until her aunt pulled me away.She claimed that I started it and acted like a 5 год old. Soon after that день she began talking to me like.nothing happened. I still talk to her bt her attitude and behavior to me is rly shady.HELP!!!