Keep it simple: Did you keep your patients alive? As long as they are safe and stable, you have done well at your job. Of course, in order to maintain stability, you have to give meds on time, F/U with the PCP as needed with concerns, etc. Basically, implement care in a timely manner. However, as a floor nurse, it is an environment of constant chaos although night shift can be really busy or okay.
When you have multiple tasks, think about which is the most important: A STAT order? A medication that if not given could impact stability? Which patient is more unstable than the rest of the team and needs more frequent follow up? You have to pause and think. I use a sheet to organize my work and ESME12 has alot of sheets that can be used for the purpose of organizing your workflow.
As far as your charting is concerned, make sure that if you did it, you chart it....Or you didn't do it (by a legal perspective anyway). Make sure that you are checking charts all day for new orders. Remember to sign those off (a huge safety and pt care issue is when charts are not being checked because it impacts the care that you give).
Nursing is stressful. Your anxiety will never go away. That is why you have to have a life outside of work and be able to vent to your nursing buddies. Again, as long as you caused your patients no harm, and they are stable and alive, you have done your job.