If you want to get your ex girlfriend back you need to discipline yourself to stop thinking about her and to focus on what you're doing instead. Trust me, absolutely no good can come from checking out her Facebook status especially considering that you know she's putting stuff up there or making comments that are designed to get some sort of reaction out of you. That doesn't make her mean or anything shes a woman and that's what woman do.
When you're trying to get your ex girlfriend back you need to focus on having fun being single and improving yourself. Go go out with your friends, hit the weights, buy some new clothes and most importantly stay off her Facebook!