You're planning to work 30 hours a week for 5-7 years ... at a non-professional job ... and save enough to retire?
I don't see this happening -- not without mouching off your parents or society.
To put it into American terms and assuming you average $10/hour over your short career, that'd mean you'd earn $15,000/year, so that'd be $75,000-105,000 total ... and if you saved 90% of that (which would require mouching off your parents), you'd have $67,500-94,500 saved, which, if you look at 4% per year, would give you $2700-3780/year to live on. Unless you're going to live and take all your meals in a homeless shelter, I don't see that working.
You've just started college. I think you're overwhelmed at the prospect of years of education and beginning a career. If nursing isn't for you -- and it isn't for most people -- my daughter's a senior in a nursing program, and well over half the people who started are no longer in the program -- you need to make a choice to do something else. In truth, a huge percentage of my students say they're going into nursing, and a whole lot of them make that choice because it's a very "visible" profession; that is, it's something everyone knows about, so it's an easy idea for young people to latch onto.
Whatever you decide to do doesn't have to be college, but you need something. Does your college have a career center? Have you tried some online personality inventories /career pathway surveys? Maybe you need some time off to work and consider your options.
Don't worry about it being too late. It's easiest to go straight from high school into college (because you're already in the student mindset, and you probably haven't taken on adult responsibilities like a mortgage or children), but college will still be available to you next year, the next year, or in ten years. So will trade schools, the military, and other paths to various careers. And attending classes without a clear direction in mind isn't the best plan.