I think you are right on the mark to view discomfort as an invitation for growth.There will always be self doubt. It's merely evaluating the possibility that you could fail, which is almost always possible.
The key for me, is to keep trucking forward. Just straight up plow through it. I now view discomfort and failure as an opportunity for personal growth. Learn from it and move forward. Failure does not necessarily mean your journey is over.
Well I think lack of confidence in a area relate to feeling weak in that area.But how do you do that?