<human>: Give me a shortened version of the text

We've had a rocky relationship lately, and in a lot of our arguments she brings up how she's spoken to some friend and they agree with her that I'm a terrible boyfriend, that she should leave me, that she can do better, etc. Usually these are unnamed friends or coworkers of hers. I have no fucking clue how to respond to this, even though it makes me really upset.

Though most of the time these are unnamed folks, sometimes they'll be my friends or coworkers she mentions having these talks with. During an argument last night, she even told my sister about "your behavior" a few weeks ago and my sister was "horrified" by how horrible a boyfriend I am.

Today we were fighting and she kept mentioning a particular coworker of mine and how this person has told her that I don't listen to her enough or I'm not supportive enough — or something, the details are always murky. This is somebody I work with pretty closely and though I haven't said anything to him, it's now on my mind during all our interactions.

Obviously we have issues to deal with, but this kind of thing makes me too upset to even try to deal with the root issues. I mean, it's true that I have one or two friends who I talk to about our relationship and who I even vent to sometimes. These friends listen and give me decent advice. But I'd never try to use what they say as a weapon during an argument.

What is this kind of thing even called? Do most people argue like this and I'm just not in the loop? I feel like I can't even respond, and I also am starting to feel closed off and weird being around people because I don't know who has a distorted or extremely negative opinion of me now.
<bot>: Girlfriend speaking to (many?) others about our relationship, using what they say as a weapon during arguments and fights. Don't know how to deal.