Friend Conundrum?

So I had this friend he didn't like my girlfriend, she has this friend doesn't like me... guess What? They in a relationship too. Anyway I realized I didn't like him talking bad about my girlfriend so I just broke our friendship off. Now she doesn't want to leave his girlfriend. Which has it's own set of issues - she is very insecure, erratic, spiteful, selfish. I find my girlfriend is now starting to adapt the same personality traits as she spends so much time with this girl
The issue is she is a drugger, she arrives at work late, she has literally dropped my girlfriend as a friend 3 x since we dated for a year. She just finds other people to hang out with or she's with her boyfriend or she's broken up with him sleeping with someone else telling them about him and then sleeping with him. She is a problem which needs to go now. My girlfriend is amazing she deserves good friends which bring her up and this girl is changing my chicks personality. It's sortof annoying me she's started lying then I catch her out. I'm just tired of dating my gf's friend (basically she adopts her personality somehow. ) ladies what is your advice? I don't want my girlfriend doing drugs either she already has done with them. I would never force her friends away but my girlfriend has become spiteful, selfish and it's a direct cause of this chick
Friend Conundrum?
Add Opinion