Hello Leyla,
It actually sounds like your manager is the one with issues, not you. She doesn't seem like a good manager if she is constantly hovering and pointing out mistakes, or what she perceives as mistakes. I think some people like to take managerial jobs because they get to feel some sense of power. It sounds like she has control issues from what you describe. I hope that if you can shift your thinking from it being all you, to it being mostly her issues, maybe you can regain your confidence. It also sounds like you have been there longer than her. Maybe she feels intimidated by you because you probably know more than her. Hopefully your day will be better.