write first edit later, try to get written down the text of the chapters you need first. now its usally 3, but contest demand 8. when you have written the entire story down, you can see how much time you have to edit it to be better. and do some more advance stuff. so just write, dont think so much if it makes sense,
its also often more easy to work with editing when you arent working on and empty canvan, and again it can ruin your writhing if you have to stop to edit it all the time.