You’ve written a book. It took you thirty years and eighty-million revisions. You’ve gotten some positive feedback from agents/ editors/ critique partners/ your mom, but you can’t seem to ramp it up to the sales-ready level.
Here’s my advice to you: let it go.
Goofy meme aside, I genuinely mean it. You can’t tie yourself to any one story. You are a writer, not a writer-of-this-one-thing. As much as you love it, as much as you worked on it, it doesn’t define you.
Write a second book. See what happens.
You don’t have to throw your first manuscript into a symbolic fire and curse cruel fate.
Print it out. Kiss it. Tie a ribbon around it. And stick it in a drawer. Maybe as you go along you will gain the tools you need to take it out of the drawer and make it into something marketable. Maybe in three years fae-werewolf adventure/romances with speculative elements will be in. For now, write something else.
You’ll go in this time with all of the research and internalized advice you’ve received while going through the hell that it is writing your first book. You are starting from a better place. You can do this, I promise. You can write again.