Your capacity and your thoughts about your capacity are two different things.
Separating your ability from your thoughts about it will help you engage your courage and act despite fears, self-doubt or whatever other self-imposed obstacles might arise. Try using this simple technique to get you moving again.
I recently had an example of this disparity between my thoughts about my ability to speak unscripted on camera, and my actual capacity for this. (You can check out the results in the video below) It has helped me to be able to identify my self-doubt as such, and then be able to remind myself that my capacity and my self-doubt are not the same thing. This separation has helped me to go ahead and do what matters anyway.
Try it out and let me know if it works for you too!