Creators, artists, makers of all kinds face periods of self-doubt. Admit it or not.
The person and the work are knit so tightly together it is difficult to tell one from the other. Separation of the work and the person is not possible. Any doubt in the work, show itself as self-doubt.
Avoiding self-doubt is utopia. Self-doubt is there for a reason. It is there to protect you against potential failure. It is there because circumstances have somehow taught you that you might not be good enough.
A pragmatic approach is to familiarise oneself with the self-doubt.
Get to know it. Acknowledge that it is there. Invite it inside. Listen to it. Examine its motives. Seek to understand what your self doubt cycle looks like. What part of your process does the self-doubt prefer? What type of opinions does it have?
Give it a name even.
And then, finally, thank it for caring, and ask it kindly to sit down and shut up, while you get back to work.