Is it me or is this person confusing?

one night me and this girl and her cousin went to the club had good time came back she was holding my arm and we were all talking. in the car she asked me if i liked this other girl i said whats it to you she said i just wanna know i said no were just friends and she said i wonder why she doesn't like me. then she tells me she still sees me as her best friend even tho we hardly talk now. all that stuff aside i called her and she called me back leaving me a voicemail to call her soo i did call last night to say what sup since i came back from my trip and she was soo blah and talked alittle i didnt understand why. I even asked her she just said i just feel blah. it was a total opposite from her that night and never mentioned anything from it. what am i doing wrong or what is she doing?