I've got a similar timeline as the OP, however in my case it wasn't fear that held my startup back initially, it was a reliance on 'old school' methodologies.

I've got a similar timeline as the OP, however in my case it wasn't fear that held my startup back initially, it was a reliance on 'old school' methodologies. In my case, I built an app about 15 years ago that was purely Windows based, and it sold like hotcakes into the small/medium business market. I then thought I could do the same 3 years ago by writing it as a cloud based system that worked on the web, and sales were way off what the previous system sold for. Reason? Because I was trying to sell it the 'old' way, and customers had moved on and were more informed now and had far more choices. It took me a while to re-learn how to do it the new way, and now sales are picking up at a steady clip.