I am in a similar situation. I graduated 2 years ago with my Bachelor's in Elementary Ed, subbed for 2 years (hated it), and wasn't able to find a steady position, so I decided to make a career change.
There are a lot of things to consider when switching from teaching to nursing...how important is time off to you (summers, holidays, etc)?, what kind of schedule suits you best (9-5 or three 12 hour shifts and four days off)? I think most teachers-turned-nurses would be able to handle the stress of the job, because we both know teaching is no picnic either.
As I was reading one of the posts above, I realized I hadn't really thought about retirement. Teachers definitely have a better retirement plan, however their salary is much lower than a nurse's pay; for example, I live in an area where we have excellent schools and teachers supposedly have great pay...a teacher who has 10 years experience and holds a master's degree will be making about $65,000/year. I am assuming that the above poster's sister's husband (the administrator) probably makes well over $100,000 and that is why they can afford extra vacations and luxury cars. It is also extremely difficult to achieve administration position in teaching; whereas in nursing there are plenty of opportunities to grow, climb the ladder, and explore different areas.
Try shadowing some nurses (as I recently did) before you make the commitment of leaving your career and going back to school. In most cases, a hospital based diploma program will pay for your schooling if you agree to work there for a year or two. I am looking into this, rather than going for a second bachelor's degree. Good luck with your decision. I hope I didn't confuse you even more!!