i hate my bestfriend

we’ve been best friends since like 3rd grade, I know everything about her, she knows everything about me. since this schoolyear she changed somehow, she hangs out with others and she doesn’t really talk to me like we did in the past. she got all b*tchy, when I said ‘stop flirting’ on a voice call a week ago so almost cussed me out and was annoyed with me. when I did the same thing in the past, she laughed and I teased her the whole month about it. she now hangs out with this boy a year younger then her, she always tells our friend group that he’s her bff and not bf!! in a pick me way. my hate to her begins to grow every time we talk to each other, which we don’t anymore because I try to avoid her. im scared to lose her since she’s a big part of my childhood, and the second reason is because in the past she had another bff that left her because ‘she changed’ and she exposed her to the whole school. n*ked pictures, secrets .. I was on my best friends side when that was happening, and I didn’t it’d happen to me..