First of all, ((hugs)), and sorry you are feeling this way. It might sound trite, but you're a new nurse, still in orientation on a busy floor; much of what you're feeling is absolutely *normal*. I felt the same way and I'm sure if you've been reading posts from others in this forum and the 'first year of licensure' forum, you see that we all felt overwhelmed, anxious, nervous, doubtful...
Think about what you've written here though and ask yourself if it's really "nursing" - as in, taking care of patients, providing teaching, administering medications and thinking through their plan of care - or the strains of working a hospital floor that you're finding so awful. I too thought I'd made a very expensive and stupid mistake - changing careers in my 30s only to find that my first job - on a busy general surg floor of a big teaching hospital - was so....awful! I wanted to quit and never go back; I tried so hard to think it through and try to articulate what it was that felt so wrong, but couldn't come up with an exact answer. I'm convinced now, two years later, that sometimes it's the transition to the floor with its demands, (many times) unsafe ratios and sink-or-swim working environment that breeds this sense of discontent. I also felt badly, because DH kept saying, "it's okay, maybe you should just switch jobs - maybe that's it!" - he tried so hard to be supportive and I just wasn't happy.
I did switch jobs - transferred to another floor, then to float pool - and I finally found out what was wrong: my hospital system was ridiculous. 11 patients at night - I should've turned in my badge and never looked back, but being my first hospital, I didn't know if things were better elsewhere. I took an agency position to do M/S float at another hospital and actually had time to sit down, go pee, eat food - amazing! Of course, part of this is that you need to give yourself a solid 1-2 years to grow into your role; you recently underwent a big change moving from a smaller facility to a larger one, with a new orientation - it's almost like starting over again, with much of the same anxiety. Most of my anxiety began to melt away as I began more and more accustomed to my patient population, skill set and job. Once those feelings started to fade, I took another job and am now in the ED. Given this path, I think I can tell you that going to a busier, more rough and tumble area isn't going to be less stressful; it will ask even more of you than the floor and utilize a different mindset and skillset than what you're developing now. Don't jump out of the pan into the fire just to flee the floor - if anything, put in your time with the only goal to develop your skills, learn and then use them to get out. Count the days, mark them off on a calendar, whatever it takes - just get through it and take away what you can.
It can get better and it does - there are many stories of proof rolling around on this website (including mine, here!). Hang in there, develop your skills and keep your eyes on the prize - advancing your knowledge and moving along to a more suitable specialty, whichever it may be. Good luck.