self distrust

/ˌsɛlf dɪsˈtrʌst/
noun
  1. A lack of confidence in one's own abilities, judgment, or worth.
    • Years of criticism had planted a deep self-distrust in his mind.
    • Overcoming self-distrust is the first step toward trying new things.
    • Her self-distrust kept her from applying for the promotion she deserved.