If your girlfriend really cares about you, chances are she doesn't realize what she's doing. That means that if you confront her about it, she'll deny it, saying she just isn't doing anything wrong. One idea might be to write down every time she does something that feels critical to you. Do that for a week, maybe two weeks. Then when you feel like the time is right for an honest conversation, you can bring up the subject knowing that if she doesn't acknowledge it, you can show her that you kept track of how often it happens. You need to be careful to explain that the only reason you wrote things down was because you couldn't figure out another way to get her to believe you and that the only way for your relationship to continue is if she believes you and is willing to change.

If she is angry at you for writing things down and/or still doesn't "get it", its time to find a new girlfriend.