While doing a new thing or doing a preparation for something every person has a pinch of self-doubt in himself. As I am a student so I generally generates a sense of self-doubt when I began to prepare for some exams. It is I think very common in every student’s life to generate a sense of self-doubt while preparing for any exam. In my point of view it generally occurs due to various reasons such as last-minute preparation of something, exhausting yourself in the preparation also generate a sense of self-doubt that we haven’t prepare enough for some purpose.
Having self-doubt is normal but overdoing anything is not good in a long term. So we should believe in ourselves and keep confidence in the hard work that we have done self doubt will be removed automatically even if it reoccurs then keep believing keep doing the hard work.