自我疑惑

例句：

1. 1. She was filled with self-doubt about her ability to excel in the competition.
   她对自己在比赛中表现出色的能力感到自我怀疑。
2. 2.He often doubts his own abilities and lacks confidence in his decisions.
   他经常对自己的能力产生怀疑，对自己的决定缺乏信心。
3. 3.The student's self-doubt held him back from achieving his full potential.
   学生的自我怀疑阻碍了他发挥出全部潜力。