Writing is, by no means at all, whatsoever, in any way, a quick and easy process. Whether it's a poem, short story, novella, or full-on novel, you're not gonna sit down and bang out a perfectly polished publication-prepared product.
Nope. Not gonna happen.
Here's a video showcasing the broader aspects of my writing life. Aside from the first draft of Embassy, I take writing slow (the first draft of Embassy was a special exception). I've been writing novels for 13 years and this is how it's gone for every single book I've written.
So sit back and learn the true time required--in scales of months and years--to produce a perfectly polished publication-prepared product (and even then, it's never perfect).