Rewriting is a large part of the whole job. And get rid of stuff that's not working. Just pare it down until it's a beautiful thing you can hand in, probably late, to your editor. ↗
When I need the idea, I can find it immediately. I have a horror of rewriting or deleting; the parts of my composition are carried in my head 'till I can write them down, even to the last note. Then I do not alter a jot. ↗