I’m amazed at just how much writing never makes it to the final product. Writers often compile massive amounts of material. The manuscript comes about through paring down, cutting out large sections, and then trimming even more.
Having too little to say isn’t ever the problem; it’s having too much.
The reader doesn’t need to know everything you know or experience everything that brought you to the project. That’s what makes you a writer: you’ve sorted and discarded, you’ve distilled and refined, you’ve narrowed everything down till it’s a beautiful little gem for your audience.
You’ve cut, cut, cut to make the diamond.