Help I need advice

I have been friends with this girl for about 4 years now. We used to hang out every other weekend. It used to be super fun but lately she seems kinda toxic? She’s been hanging out with other friends all the time and she can’t take time out of her day to text me. At school she blames me for things she does that her friends don’t like. When she does text me though she won’t talk about what I want to talk about she just changes the subject to talk about a boy that she has a crush on. The boy isn’t a good person. I can tell by the way he texts her. She always tells me I’m not strong and stuff like that which gets annoying after a while. Also lately she’s been involved with things she probably shouldn’t be. Her friends aren’t good influences at all. I tried to stop talking to her for a while but she is the best friend I’ve ever had and I can’t stay mad at her :( All she ever does is come up with excuses for why she doesn’t treat me right but I still always forgive her. What do I do??