Listen as much as you can to other lessons. You learn so much from observing! The teacher says something and you simply notate it. (I even have notes from masterclasses saying “don’t teach like this”.) And don’t be afraid to ask questions. If you don’t understand why you should or shouldn’t do something, the teacher has a duty to tell you.
A career in music involves constant challenges – musical as well as career-related. Striking a balance between absolutely believing in your ability to offer something meaningful and original on the one hand, and being super critical of your playing at the same time is certainly challenging!