Should i end it?

(Both in high school)
Ive been dating this girl for over a month now. I've always known her to be a flirty and fun loving girl, until we started dating. She turned into this person who doesn't like to communicate (facebook/texts calls/messages) with me at all. Let me explain further, she never calls/texts me or says anything to me in any way other than in person, like keeping in touch with me doesn't matter to her. We kiss and stuff, we arent like a couple who dont get close or something. Only at school do we hangout, occassional dates and whatever. In person she jokes about seeing other guys than me and that everyone likes her/stares at her and all this bullshit i can't stand to hear. She talks in a sarcastic/awkward tone all the time now too, super annoying. Has she lost feelings for me, and doesn't want to tell me? Or does she feel sorry for me in some sick way and is manipulating me? I don't know if i should break it off or not.
Thanks for the help.

Break off what? You have nothing, thus nothing to quit. There is no relationship here.
All yo are doing is pursuing a girl that is not interested. Stop stroking her ego and pursue someone esle ho might be interested.

The options that come to mind are that either she's particularly insecure or she has a personality disorder. Consider you're both in high school, I'm going to go with the former.

There are better girls out there.

Thanks guys, appreciate it