Hang in there and keep telling yourself that the empire state building wasn't built overnight so you can't learn all there is to know about patient care in a short amount of time either.
It does take time to feel really grounded and comfortable in performing RN duties. The way nursing is today doesn't really help new grads any, but if nursing is really what you want, don't give up!
All nurses have "cold feet" in the beginning. When we're students peforming clinicals with our Instructor close by, we have the time of our lives, and are anxious to graduate, pass boards, and start work as RNs. But, once we accomplish those tasks, and finally are able to wear the proud title of RN, panic sets in because now "We are the Instructor" -- the Captain steering our own ship -- if you will.
Keep reminding yourself that all those seasoned nurses you work with at work who seem to have everything down pat were once in your shoes and felt the very same way. And, in time, you too will become a "seasoned nurse" that a "new grad" will look up to saying "Wow, how do you do it!"
Don't get discouraged! Anything worth having is worth holding onto and working hard to master! I'm rooting for you! :kiss