When you doubt your power, you give power to your doubt.

Doubt feeds on attention. Turned over often enough, an uncertainty stops being a question you are examining and becomes a verdict you live under. It begins making decisions for you by keeping you away from tests that might disprove it. The trouble is not having doubts, since nearly everyone capable of anything has them. The trouble is treating them as reliable information about what you can do.

The remedy is usually evidence rather than argument. Pick the smallest real test of the thing you doubt about yourself and run it this week, so the question gets answered by what happened rather than by how you felt.