Those days WILL come.
They are the days when you look up from your manuscript, look at the shelf at the store, and wonder why all of these books are there that say the same things and do the same things and differ only in the trappings- and yours is no better.
They are the days when you look down at your manuscript, and all you see is a rancid word salad despite your best efforts to write and edit it into shape, and wonder how and why others like yours got published- nevermind success or failure.
They are the days when you look around to hear reader after reader after reader make your ears bleed by talking about the cavalier manner in which they read and thus miss all that you put into it.
They are the days when you look out for answers to questions of art, of craft, of narrative and you realize that not only have all the questions already been answered, but that the solutions are already known and perfected- that you're struggling with a solved problem, and then feel like a fucking moron who can't tie his own shoelaces.
They are the days when you learn why writers have the reputation of being moody, melancholy, and prone to self-destruction. Writing is a craft, sure, but also an art. Art demands revelation, and revelation cannot be controlled.
You don't go digging into places immaterial, mining the depths, without making discoveries. If the craft is the acumen and discipline that takes inspiration and hammers something others find useful, then the art is bringing forth the ore to be hammered.
Learning how to handle these days is part of the process, and it is initiatory in its nature. Not everyone who makes the attempt survives, and not all those who survive do so on their own. For my part, knowing that this is a solved problem gave me that fortitude; apply solution, sorted, and the problem gets reduced to an irritant.
And that is what I have to say today: you struggle with a solved problem, so all that needs doing is to find and apply the solution.