So My girlfriend say "I want space." Yes, yes I say "sounds like you want a break-up"?

Keep in mind she has said this before. And what she tells me is "No it's not" and gets very upset. We fight and always say at the end things will get better. However, the same fight (maybe in a different ways) Always happens again. She always ask me to open up and when I do things just go down south... I tell her how I feel and she say I am being over sensitive. Now I know this seems feeble but on "facebook" She will say things like "I put so much into nothing" and before I assume its about me I'll ask her about it. In the end it comes out that it was about me. but tells me I shouldn't read into. I just need someone to give me another respective on what or how I should handle this.