Your novel may be well-written. I wouldn’t risk a guess. All I know is the worst writers I’ve ever met have also been the most convinced they were God’s gift to literature.

That said, I can sympathize. Selling a story is hard, and luck is a huge factor. If the next Hemingway is out there, they’re probably getting sick of hearing “sorry, this story didn’t work for us. We wish you the best in placing it elsewhere.”