I would like some advice, please.

[DolefulMusic303]

I have this 'friend', who I thought was my best friend. I'm dating her ex (which trust me, I feel horrible enough about it,) and she will not shut up. She constantly talks about what they did together, bashing him, saying 'Oh, you should break up with him before he does with you.' It's torture. I've never been good with telling people off and removing them from my life. (I;m still dealing with this girl I've tried to get rid of for years....) I was deciding whether or not to break up with him, and I told her in hopes of her understanding and helping me get over it and be happy I'm even in a relationship.
Instead, she goes 'Yes! Yes! Do it! Do it the way he did it to me! Payback!'
This made me upset, but I shrugged it off. Then, at her pool the next day, he texted me. She began texting him with her usual stuff. (Every time I go to her house, she'll call him on my phone and say 'Hey baby! Miss me much? I miss you, I love you!') Still shrugging it off, we leave our phones and go swimming. In the pool, she talks about how he's such a jerk. Luckily, we leave then. I've tried not to talk to her since.
This sin't the only thing she's done. She'll bash on my family (even my dead ones. She got angry with me because I couldn't talk to her when my grandma died, and yet she expected me to be the bestest of friends when her grandpa died.) She's rude to my friends who she doesn't like, puts me in bad light, (calling my ugly, fat, saying I suck at art and singing,) and tries to get me to do things that are wrong, like sneaking out and stealing. Stealing!

I have no idea what to do. I'm normally too nice, and I don't want to be pushed over the edge just to get rid of her. I don't have very many good friends I can talk to......

[hipstersquirrels]

The girl sounds like she's insecure, jealous, and using you.
She's insecure because lol, you got her man, der. It's normal to not like the girl your ex moves on to, but she's taking it to the extremes. Jealous for the same reason. And she's using you to stay in contact with her ex, who is now your boyfriend, and using you as a gateway into his new relationship. Basically, she wants to fuck you and him up.

What I would do, is confront her. Lay it down, nice and clear, and be strong and bold about it. Tell her what she's doing wrong, how you feel about it, and tell her it ends now. You're going to have to stand up to her, or she'll just continue what she's doing.
I'd also have a little one on one with your boyfriend, to be sure you're on the same page about it. He's supposed to be there for you, it's part of being in a relationship. So yes, you do have someone else.

[IzzyRod]

Give her a stick and tell her to shove it up her ass.
People like that piss me off.
First off, she isn't a real friend at all. If you really like the guy you're with, then STAY WITH HIM. don't break up with him because that girl is telling you to. She's just jealous and wants to fuck both of you over.
Second, tell her to calm the fuck down and leave you alone. if you still want to be friends with her, sit and her down and tell her how she's been acting and how it makes you feel and how it upsets you. Being nice is great and everything, but sometimes people cross a line, and you can't let them cross it. You have to stand up for yourself.

[PLucy]

She wants you to break up with him because obviously she's jealous and can't stand that he broke up with her. But you shouldn't break up with him if he makes you happy, neither should you allow her to call or text him from your phone because you never know what else she could say to him, it's weird, and it's not you.
She needs to move on.
However, you also need to move on. From her.
She is completely negative and jealous and you should not have that kind of person in you life. If you continue to let her control you, you're gonna end up on the shit side of the stick, not her.
Gradually stop talking, hanging out with her. But if she does one more fucked up thing, tell her: That just wasn't cool. I didn't like it. END IT THERE. No discussion. It's not mean just straightforward.
Don't let people control you. She is just jealous because you are "better" than her.