Nothing gets in your way more than a creative writing degree and a lot of practice doing other kinds of writing, both of which fill your head with all sorts of ideas about what writing should be like.
If you're feeling the urge to go back and fix (or despair over) what you've written already, and if it's getting in the way of powering on toward your goal and your deadline, this post is for you.
Do your best to get away from "I should be able to do this" and bluntly examine whether it's a good idea for you to do this.
Self-criticism is incredibly painful, because we know where all our own weak spots are. But by that same logic, we can also be our own best allies, cheerleaders, and friends.
If no one reads your stories about queer girls in space, that's not a judgment on you. And if everyone loves your stories about queer girls in space, that's not a judgment on you. The work is the work.