Spending a few days or weeks on the business model can save months of sacrifice, especially when building a product that is saturated with competition.
Painful, yes. A waste of time, I don't think so.
Although I would never recommend building something without understanding the business model, all is not lost. OP probably learned more valuable lessons (and technology) in that 8 months than he would have in a job or at school. Now is the time to put that education to work. Not doing that would make it a waste of time.
Because of this product venture, I'm currently working on something much more promising because of the lessons I learned on this one.