I have a backstabbing friend?

I have a 'friend' who I desperately want to free myself from, or let her know how pissed I am at her, but there's a bit of a problem. I can't just start talking less and less to her. We have EVERY friend in common, against my wishes. Every time I make a friend, she needs to know them too, and become closer to them than I am. And also, back in 8th grade, I invited a few friends over, but not her, and she noticed since she lives right across the street from me. Her mom called to get her invited too, by implying, but my mom was so amazed and insulted she played innocent and wouldn't let her over. After that, she sent a rumor around to all my friends saying I couldn't be trusted. She convinced all of my closest friends. All of her 'attacks' come after she learns im doing something with other friends, and she purposely picks up her phone when im over when one of her friends call and she makes plans with them right in front of me. Maybe im alone in this, but i think thats insanely rude. So, basically, if I lose her, I'll lose just about all of my friends since she'll start another rumor, I'm sure. And then she lives next to me. Please, what should I do??? I've been trying to deal with this for YEARS!