Help please

Okay. So my boyfriends best girl friend was my best friend up until March when she broke my trust and started telling him things I had said about him to her in the past and she even told him some lies too which I made sure he knew it was a lie. She would indirect me all over social media but my boyfriend never thought it was about me or towards me so he wouldn’t listen when I would tell him that she’s out to get me and there was so much proof yet he was so oblivious because that’s been his best friend since they were like 5. Fast forward to last month and she texted me saying that if I wanted to talk things out, she would do that. So I thought we were beginning to be friends again. Well turns out she’s been talking about me again and she blocked me on every social media. She lied to this one girl and said she was forced to come celebrate my birthday with me which was a lie because if she didn’t want to come, she didn’t have to AND she spent money on an uber to get to the place for my birthday so yeah I forced her to spend her own money and drink when she didn’t even pay. My boyfriend did and that’s a whole nother story. She mooches off of him but he doesn’t see it as that either. 🙄🙄 Idk why she’s being like this to me when I haven’t done anything to her. I want to tell my boyfriend because she’s toxic and has done so much to me and in general but I’m afraid he won’t do anything about it. He never did so why would he now? What do I do?