Relationship Issues, please help?

[Happyanimal523]

Okay so I've been with my girlfriend for a few weeks now, I know what you're thinking, it's only been a few weeks but the fact is we've been dancing around eachother for a while now
Everything was great between us, we were getting along famously and she seemed to adore me.
She spends a weekend at my house and then as soon as she gets home she starts playing up.
First she says on her facebook that she has feelings for someone else and she wants to break up with me. That pissed me off mainly because she said it in a place firstly where other people could read it, including myself and didn't just say it to my face
Then we break up because of that stupid comment
And then we get back together ON THE SAME NIGHT cause her explanation was 'attention seeking'
She's been really cold towards me since and hasn't been communicating to me as she usually does, but she's been the same with everyone else
And i'm starting to think she DOES like someone else, and she's not just bullshitting about that

I'm not sure what to do
I like her a lot but should I just break up with her or stick with it?

Help please