FWIW, your ability to self-reflect makes me excited for your future. There is nothing to "fix" with respect to self-esteem and confidence. Just observe those thoughts as they arise and laugh at them. We all are novices. We just happen to be at different stages of our own personal development.

"Young man, in mathematics you don't understand things. You just get used to them." —John von Neumann[1]

[1] https://math.stackexchange.com/questions/11267/what-are-some...