New grad nurse here, I'm 6 months into my nursing career so school is still pretty fresh in my mind...I don't know what kind of classes you enjoy but i'll share my experience. I really enjoyed my prerequisites and liked taking those classes (microbiology, anatomy, physiology, chemistry etc) more than I did my time in nursing school. I honestly felt like I could have gotten my BSN completed in 3 semesters instead of 4 because everything was so drawn out which made the experience not as interesting as I thought it would be. But thats just my experience...I know a lot of my peers felt like 4 semesters wasn't enough so it depends on your learning style. In terms of how prereqs compare to nursing school courses I would say they're pretty different. However, you will spend a lot of time talking about psychology and sociology related topics especially during psych rotation, community nursing, pediatrics and leadership and management etc. So if thats something you just can't get through....nursing school might not be very enjoyable.
As far as knowing whether you want to be a nurse, again I'm only 6 months in but I have days where I feel like i'm doing great work and other days where I feel like I made a huge mistake. I agree time is the only way to know.