Welcome and I have some advice: Switch the "nervous" for positive tension. It's good to never feel "safe" and relaxed. Most of the nurses I work with -including me- say they always have a feeling that something COULD happen and the tension from needing to be ready for whatever happens.
A coupe of times in nurseing school I let my nervousness get the better of me and guess what happens when I do that?
1. I get behind on my meds
2. I don't do my best work
3. I make stupid mistakes
4. My patients think I'm a spastic psycho who shouldn't have a needle in her hand!
It'll be okay, I promis!
Feel free to PM me any time!