Sometimes I think there’s only one piece of writing advice. “Finish it.” Finish the novel, finish the short story, finish something and then edit it or move on to the next thing and learn something new.
I don’t care if it’s bad. You can’t do anything with a story that’s in scattered fragments. And if “finishing” means discarding a piece that’s beyond repair, and starting on something new which you are able to finish, that works, too. I did that with two novels in a row.
You can’t get anywhere as a professional writer if you never finish anything. Or finish with anything.
Finish something. Just one thing. Worry about the rest later.