You sound just like a new grad. Welcome to being a new grad. You'll mess up. You'll forget things in the charting system. You'll slow your preceptor down. You'll have your hand held. Don't take that personally. You're supposed to. You'll forget how to hang something or what settings to turn the pump to. You'll be unsure of what meds you can give, how to give it, and ask countless questions that any other nurse should know. My preceptor told me "better safe than sorry". Question everything and anything, don't feel stupid. If she had a question and I couldn't answer it (like, what a med we spent two seconds on in school was for or how it would help a particular patient) she went over it with me. I was lucky to have a wonderful preceptor and when she wasn't on those who filled in were equally as great. I hope you do as well. My Educational Outcomes Director was constantly on me asking me how things were going with my preceptor. Now, that wasn't to say there weren't some days where I stepped on my preceptor's toes or made her eye twitch. Of course I did. There's a fair amount of "I want you to develop your own methods and ways of doing things, while at the same time, doing exactly as I show you and tell you". And I understood this. My screw up isn't just my screw up, it's hers too. My first week was pretty much shadowing and learning the system (we have Cerner), that next week I had two of our 4/5 patients. No one ever said to me "wow, you've been here two days, you can't handle your own patient load yet". If I felt like the patient was giving me a strange look all I said was "Hi I am Miss.Leo, I'm new to (facility name) and orienting with (preceptor name) today."
The third week I was doing all the charting and most of the care, as well as (trying to) give report (she'd had way more time to look through the chart and even pin down doctors for questions than I did and would help out), though my Preceptor was over my shoulder the entire way and she still made sure to be right there when I gave meds. Some days were seriously hard. I was expected to hit the ground running and get right to it, sometimes without a full picture of the patient. Some days I went home and my mind was blank because I wasn't even sure what I accomplished that day. It wasn't until Week 5 that she was letting me go my own and then following up afterwards.
By the time she said goodbye to me and passed me onto my night shift preceptor, I could hold down a full patient load, had no issues with charting, was skilled in tracking down doctors to ask questions (it was important to the floor that new grads felt comfortable paging, calling or talking to doctors, especially if they were gonna be night shift), and managed report easily.
It all comes with time. As long as you are improving... you're doing fine. So you're first few shifts or even your first two weeks felt like a disaster. Are you repeating the same mistakes or did you learn from them? If you're struggling, let your preceptor know exactly what you are struggling with. "I'm not too familiar with this charting system, can you double check to make sure I've covered everything". Make a check off list for charting if you need to. Carry a clip board with notes of things you need reminders of. Mine had IV times, pump settings, important extension numbers, charting reminders, whatever I needed.
So, in short... take a breath. You're doing just fine.