Just out of curiousity, why are you considering a complete (kinda) turn-around before you have entered the job market in your field, after you've spent a great deal of time, and I assume $$, in your pursuit of your Bachelor of Arts?
I assume the "certain courses" of which you speak include Anatomy and Physiology, Chemistry, Microbiology--those classes, am I correct? Well, those classes would be required regardless of whether you ended up with a Diploma in Nursing, an Associate of Applied Science degree in Nursing, or a Bachelor of Science degree in Nursing, not to mention the nursing curriculum itself.
Since you seem to be a tad undecided, I would suggest that you explore the field of hands-on healthcare by becoming a certified nursing assistant. This would give you a wonderful opportunity to experience nursing the way it really is, not the way "E.R." portrays it to be. Our school requires all incoming freshman to go this route. It serves two purposes: one, the student can support her / himself during what time they have free, should they choose to do so (Bless them, they rarely have the time), and, second, a great deal of Nursing Fundamentals is pretty much these sorts of tasks,
so having the CNA prior to entering nursing school frees up time for other skills and competencies.
Look into 2nd degree programs as Nancy 1 suggests; there are more options in healthcare with a BSN.
Also, I would remind you that regardless of which path you choose, you still must take the NCLEX and pass before you are an RN; it is not a degree, but a license that enables one to practice the profession of nursing.
Should you decide to do this, you will be entering into a rewarding and exhausting line of work. Good luck.