I earned a BBA in Finance and Business Economics. I had no problems whatsoever with the science prerequisites and gained admission into a highly-ranked BSN program for Fall 2011.
I started my prerequisites in Aug 2009 and finished in December 2010; however, in order to achieve that feat I took two science courses a semester as well as eight credit hours during the summer; I basically went to school year round. It is a lot of pressure too; the nursing programs
are competitive and you need to get the best grades you can in your science prerequisites. I felt I had to earn an "A" in every class to be successful. But that is what works for me.
Take your time...maintain a prudent class schedule...no sense in busting through the prerequisites if you are only going to earn average grades. This is not a sprint...it is a marathon. There will be just as many ADN/BSN programs available to you in twenty-four months as there will be eighteen-months from now.
The bottom line is it doesn't matter in what discipline your previous degree was, or where you worked; it is about having the desire and dedication to persevere through the bad days and self-motivation when the doubts start to creep in your brain.
You can do this no problem...you have the experience of a four-year degree behind you, which is more than most people with whom you will be taking prerequisites will have. Lean on that experience and it should serve you well.