I have been an RN now for over 3 years. I started out as an RN in the hospital setting working Med Surg. and I now work in OB.
Honestly I was a wreck for nearly the first year. I thought the same thing you did, "Is nursing right for me?" I was worried I did something wrong, or missed something everyday. I made little mistakes often and beat myself up over them for weeks at a time!
Experience is what builds confidence. You have the knowledge to do nursing now, but it takes time and experience to build up confidence in yourself and what you are doing.
Things will get better I promise! Some of the things that seem stressful to you now will just be routine later. You are learning from all the little mistakes and you will turn into a very good nurse!! Be patient, and have lots of support during the first few months.
Hope things get better for you, and keep us posted!!