Jason has explained the situation and how to change it to your favour - I agree with his assessment.
Let me elaborate a little and add some specific exercises you can perform.
As per the previous answer: you have to sell something before you build it. You can still - in a roundabout way - go back and do that. Set up meetings (real or virtual) with five top customers (current or prospected) and let them do all the talking. Ask about the current solutions they have in place, what they like about them, what is lacking, what changes often for them, what other parts of their business can affect that part that your product touches.
In addition: 2 exercises for you.
1 - Assuming you are B2B: Understand the buying hierarchy. There is your client, the buyer (the individual using the product) and the end client (the person it serves). This might be 3 separate people, or 2 or 1 but you must understand those roles. More here:
2) Understand your buyers' needs from three perspectives: Technical (how they want to save time and effort), Business (how they want to impact the business bottom line), and Personal (how they want to improve their own lives). More here:
This should help get things moving.
If you want to discuss further, or assistance in these exercises, I am available.