Hi llc,
Reading your post really took me back in time and in fact,I could've written those very same words. My guess is that this conversation could happen any time in the history of nursing, or for that matter, any profession. What you're experiencing is called many things; initiation, work hardening, earning your stripes,and so on.
When it comes to nursing, newbies however skilled, tend to feel inferior to their more experienced coworkers and it doesn't take much to feel overwhealmed even when you do everything right. You can be sure that wherever you go, there will always be snipey nurses who relish any opportunity to sprinkle "I feel like an idiot" atoms on you when you are vulnerable. They tend to be most noticeable and inflict a lot of pain but there are also those kind and patient mentor types who will support, guide and encourage you. Look for them.
This really is a formative period in your career, more than school itself so be really careful how you handle it. While your clinical skills develop, so does your professional conduct and in a few years you will either be the negative undermining snipe or the calm, confident mentor.
Good luck,
R