I am currently finishing off my last pre-reqs to get into nursing school. Overall, these science classes are quite intense and challenging. With that being said though, you do learn a lot! Which is great because college is the time for maturity.
Anyhow, I will say that being a science major probably takes up more of your free time than a liberal art major. I might be wrong, but I think that in science you have to make sure you are understanding every concept, because if you miss something in the previous chapters you'll be confused and behind in the next chapters. Therefore, it's important to study everyday, becuase you can't afford to procasinate. It's not like some other classes, where you can study the day before and ace the test, or make up an answer. Furthermore, I would also consider the lab portion as an additonal class.
When I am in school, I don't have much free time throughout the week. My days go by very quickly, but I enjoy the busy package
With the right studying habits and time managing though, you should be able to have most of your weekends off though
.I know that in nursing school, there's a lot more material to be covered, and you'll have to do clinical hours. I find such experience quite exciting though. Most of the time, I feel extremely energized and happy to be where I am. I guess such feeling comes from the fact that I am doing what I love and staying busy. Yes there are days where I feel dissapointed and get pesimistic(espcially when I haven't gotten enough sleep lol) but it's like everything. In the end, it all pays off!
I really recommend you finishing off Chemistry, and take any general Bio course before you take A&P. You'll grasp the material much better having some sort of science foundation. I also recommend that you get some sort of hospital experience or shawdow a nurse. Best of luck !