previous posts have mentioned this: the problem is that you're studying a subject you hate. Have you ever said to yourself while you were stuck in some stupid class in high school, "I won't have to take no more of this ____(whatever class) in college", "can't wait to get to college to take more of _____(a class you actually like)"? most people have and that's because the point of college is to study something you actually care about. If you hate the sciences, then why are you in it? what classes did you like in high school? WHAT IS YOUR PASSION?? because whatever your passion is, that's where you'll be successfull. my feeling is that you're only studying to be a nurse because you don't want to take a chance at something else that may not have such a clear future. you want to take the safe way, the sure way, so that way you'll never get disappointed. and this is where you're going wrong. Take a chance. study something you love even if you have no idea what's gonna happen to you in a couple of years. Just go with whatever feels right and learn to HAVE CONFIDENCE IN YOURSELF. If you study something you love, you'll dedicate 200% of your time and effort to it, and thereforeeee your chances of failure decrease dramatically. on the other hand, if you study something you hate, you won't put much effort into it, and you will ultimately fail. so, really, think about what you are passionate about. If nothing comes to mind, then that's a red flag telling you you need to get out and discover new things.
good luck!