How do you know when you’re making it better?
The conventional wisdom is to rewrite and revise.
I once heard Grammy winning, super hit songwriter, Craig Wiseman give a talk to aspiring songwriters in Nashville. Allow me to quote from memory: “Songwriting is like building a birdhouse. And when you build your first birdhouse, its going to look like crap. Adding paint and decoration isn’t going to fix it. Too many beginning songwriters waste time repainting their first birdhouse when they would learn more by building a new one.”
He went on to advise writers to write hundreds of songs. Because only once you’ve done the practice do you develop any proficiency.
Finish the project you’re working on. By all means, fix the mistakes, the typos, the continuity errors.
Then move on to the next one. And the next. And the next.