Well, I start my first nursing job on Monday, so I'm not sure I meet your criteria to already be working as a nurse... however, I'll chime in anyway, ignore if you want.
I've been in corporate I.T. for almost 20 years. I'm good at it, but I don't like it anymore. About 5 years ago I started thinking what I want to do for the rest of my life, and it wasn't I.T. I was a paramedic for a couple of years before going into I.T. (long story) so I already had some exposure to the medical field.
The biggest advice I would give career changers is:
** Find a way to get some exposure to the real world of nursing. Too many people go into it thinking it's going to be something that it's not. After you've already completed several years of schooling and are ready to enter the profession is NOT the time to figure out you can't stand it.
** If you can swing it in any way shape or form, get your BSN now. If for financial/scheduling reasons you have to go ADN, plan to bridge as soon as humanly possible.
** Take a hard, clear-eyed look at your home situation and your financial situation and be realistic about what you can and cannot juggle. I had no choice but to work a 40-50 hour a week job (but they were very flexible with my schedule) AND go to school, but luckily my kiddo was already a teenager and I'd ditched the ex-husband. I also am lucky that I grasp concepts quickly and so didn't have to spend *as much* time reading as some of my co-horts. It was still a living hell, and I wouldn't suggest it to anyone. If you can quit your job or work part time, it will be easier.
After all that, the ultimate bottom line is to find a way to follow your heart. I firmly believe that we shouldn't let ourselves be trapped by a paycheck in a job we hate.