What To Do?

Ok, so I am thinking about going back to school to get my master's degree. I have the kind of job now where I can do this easily. I am working three 12 hour shifts for hospice from 8p-8a from home on call. Some nights are busy, other nights there are no calls. I am home during the day. I need to get my masters because of the late start I got to my career. I am getting ready to have two kids to send to college. In my head I know I need my masters to make more money, but my heart does not feel passion for anything! I will have to take the GRE' exam and a statistics course before I can even get into a program. The only thing I can think of right now is the Nurse Practitioner program but I am not sure I want that much responsibility or to work that hard!! The only other programs are in management or education and I don't think I want to do either of those either. Becoming a NP can mean a salary of over 100k a year. I keep waiting for that to inspire me but it hasn't yet!

I would love to hear any ideas from anyone. Should I just start taking classes and see if I am inspired? Does anyone know of any other programs out there? Anyone taken the GRE or statistics? I am petrified of them both! I would really love to spend my golden years travelling the world and financially secure. By the time I am in my 60's there will be no Social Security left so I know that I will probably have to work until I am 80!

Any Thoughts? Suggestions? Ideas?