When we doubt our self, it is usually an indication that we are performing for others. We want to look good, sound good, and do good. Essentially, we want to be who we think others want us to be.
Doubt disappears when we stop performing.
We might think that the alternative to performing is being. Being what? Being the self that we already are and want to be. Being authentic. But being authentic is also performing. If we have to think about who we already are, we are performing authenticity. Thinking is what gives birth to doubt.
The true alternative to performing is authenticating. Authenticating is happening when you are unaware of being good. You unconsciously demonstrate who you already are. Then you will be a little surprised when others remark about how good you looked, sounded, and did because it was not for them. It was not even for you. It was authenticity authenticating itself for its own sake.
So, when doubt comes again, welcome it.
Doubt is a gentle knock on the door of authenticity; not to let doubt in, but for authenticity to come out.