You say you are young, but you clearly have valid concerns beyond your years.

I think everything you are feeling is completely normal. Nursing IS scary and doubting oneself is a huge part of this process; the humbling part in particular.

Like BenzieBox said, keep it light sometimes. You're academic career started young, and you chose to enter one of the more challenging paths. Of course it is important to take this seriously, but it's OK when shit doesn't go swimmingly well. You're going to have ups and downs, but the key to not drowning yourself in the downs is acknowledging that you're going to go back up.

Your passion and commitment shines and I think you're on the right track.