Personal question here, so don't take this the wrong way. Are you a "type A" perfectionist? The reason I ask is that some parts of your post make me think you might be, just like I am. I think most nurses go into this wanting to genuinely help people. Add to that the need to be "perfect" if you are a type A who wants everything just right, and it can be difficult.
My first year, I beat myself up every night, second guessing every decision, and making myself feel bad because I couldn't live up to that perfect example of a nurse that I wanted to be and that I'd been taught about in school. I thought I must be the worst nurse ever because I found myself so task oriented and just trying to complete what I had to do, like a checklist, with no real time to spend personally with each patient. In your first year, this is normal. It's hard to be therapeutic and perfect when you have to learn how to do basic tasks, how to send lab off, who to count on when things go wrong, and all the other myriad tasks you face as a new nurse.
At around 6 months out, I started to realize that I knew a "few" things, and stress was reduced a lot. At a year, I realized that the things I used to think were difficult and somehow magical were becoming routine and easy. People were starting to ask me for advice, and sometimes I knew the answers, lol. After two years, I felt really, really confident with the caveat that I still had plenty to learn. Each year it gets better and easier, and I can focus more and more on the patient.
But some days are just horrible, and it doesn't matter how much experience you've had. This is often a staffing issue- not enough help to do all the work. On those days, you just have to tell yourself that you did the best job you could with the resources available. I refer to it as nursing utilitarianism- sometimes the best you can do is to bring the greatest amount of quality care and kindness to the greatest amount of people, and call it good enough. It's official, staffing and the current healthcare climate have assisted my transformation into the John Stuart Mill of nursing.
When you are tempted to pick apart your performace, try reminding yourself of all you did accomplish that day that few other people could have done. Maybe it was just a kind word or a smile, but it may have changed someone else's attitude or life.
It sounds silly, but I was having the worst day last week- hormonal, fought with a friend, lost my debit card, you name it. Everything was going wrong. Traffic was horrible, I was trying to get to my bank in time to withdraw cash in person, and a man smiled at me and let me in to traffic. Then at the bank another man held the door open for me and said "good afternoon!"- tiny gestures, but when I got back to my car, my attitude had totally changed from borderline nasty to grateful for the small kindnesses in the world. As nurses, we have the chance to offer kindness to others every day. Some will accept it, some will reject it. What they do with our kindnesses is up to them, but it can really change your own outlook. I learned to fake a smile and a good attitude early on, and before I knew it, it was real, lol.