I don't know how i feel about my girlfriend anymore...should i break up with her?

I feel like my girlfriend is really disrespectful towards me these days. I feel like i just can't be f"$#ed with her anymore..some days she seems ok but then there's other days where i just don't want to hear her voice. Just lately she went on a work conference and came back with such an arrogant attitude that i just couldn't bare, i told her straight up that if she doesn't stop this arrogance i'm hanging up the phone and she pretty much says fine whatever i'm not chasing after you....Anyway my point is is that i feel like she's just using me as a boy toy alot of the time. Honestly i'm not the type of guy to put girls in their place, i just hope that girls reflect on themselves and change, however my girlfriend isn't the case. She thinks she's perfect and won't change, and she's told me this over and over again. What should i do with her. We've talked about this and everything but she's stubborn as hell.....please help