I think a great way to stop this behavior is to make our mirrors reflect what we love about ourselves inside and out and how we want to view ourselves (which is different from changing what we don't like). You can do this by writing on the mirror in lipstick the physical and inner beauty features you love about yourself. That way, as you've accomplished some of these things, you'll be able to grow in finding and loving yourself. For example, you may love your luscious lips and that you are a sensitive woman that shows her emotions. You look at yourself in the mirror everyday so this is a daily reminder of what you love about yourself. So it will start your day in a positive view and will build your confidence.
A stronger approach is to create a mantra that you say in front of the mirror every morning. It's more powerful than writing on the mirror as you're speaking it into existence. You can actually do both for the ultimate effect. Use the positive reflections you wrote on the mirror as your mantra and if you don't have time to recite your mantra every morning, you still have the writing on the mirror. Let's face it, no matter how much in a hurry you are, do you ever forget to glance at the mirror?
I've used the "writing on the mirror" method for what I want to achieve out of life and it keeps me peaceful, motivated and joyful. Using one or both of these methods will likely do the same for you as it relates to your confidence level and loving yourself just the way you are.