My best friend hates me? HELP!?

OK well I'm best friends with a girl called Polly but she's always mean to me. Like she'll laugh at me and be mean to me at the slightest thing I say. For example, I wrote a status on Facebook asking if her and some other people wanted to come to my house one day in half term and she commented saying stuff like, "I don't want to come to your house you moan a lot like now" and, "You're such a fail no one's gonna come they're all gonna go to Izzy's house". I apologized to her even though I had nothing to apologize for and she was like, "Um ok" and didn't really say anything else. What shall I do? Shall I ditch her?