Yes, my confidence does waver. My mood, emotions, thoughts, and experiences all effect it.
How is it overcome? I think it takes a lot of effort. I think having a good therapist really helps. Having someone you can talk to and help you through it helps. Even if you have friends and/or family that you can talk to, I think having a good therapist is still helpful. And thankfully I do have a good therapist.
I'm not entirely sure how to overcome it, but I think that at least part of the way you overcome it is similar to how you overcome a lot of things.. I recently saw someone mention
this blog on another forum. It seems pretty good, and the blogger mentioned some books that really helped him overcome self-consciousness. One of them, The Four Agreements, seems pretty good, and has helped me a little and I haven't even finished reading it yet.
I've noticed that for me personally, going to therapy sessions along with ready good self-help type books, blogs, and internet posts, whether they are meant to be motivational and are a little cheesy, or are just a little thought provoking and only cause me to think--not act--is slowly causing me to become more aware of myself and more aware of what I am thinking, and what my emotions are each day and in different difficult situations. And slowly because of these things I am finding it easier to work on changing myself. It's happening a lot slower than I would like it to, but it's still happening. And since I'm only 20 I probably have plenty of time.
It's not easy and it's not quick, but it can be done.