I would actually say that you have gone about the process in the wrong order. That is to say, you should start off by talking to your clients /first/. Figure out what their problems are. Collect all of that.
Then, come up with a concept tailored directly to their problems. You probably need no more than a 1-3 slide deck to show this to them and figure out whether the concept is desired by your end customer.
Finally, and only once you've validated that the concept is desired by your end customer, you build the product.
The problem with doing it in the order you've mentioned, is what happens when you go and show your product to a customer and they say "Nope, I don't actually have an issue which your product solves. Thanks but no thanks."
Sales is the beginning, middle and end of your journey as a founder. Building the product only comes in over time once you've found something worth selling.