After being a nurse (diploma grad) for 20+ years I would have to say there are many positives and negatives to nursing.
The essence of being a nurse is caring for people - there is no work more rewarding than this.
Nursing offers more specialties to choose from than most other professions, as a nurse you can specialize in maternal-child, OR, ER, med-surg, home health, school nursing, and many others.
The biggest negative is that many times because of short staffing, budget cutbacks, etc, nurses are not able to give their patients the quality of care they want to give - this is very demoralizling, and is the main cause of burnout for nurses, especially if it happens on a daily basis.
If you feel called to nursing, I would recommend attending a BSN program, with the intention of going on to graduate school. This will open up more job opportunities, and increase your chances of finding a job situation that truly suits you. Don't think that you are "too old", because I will be finishing my BSN this year at the age of 48, and I am not the oldest person in my class!