Hey, thanks!
I think that when you go back and re-read your writing for editing purposes, you shouldn’t immediately discount ALL the writing as being awful.
Instead, look for parts of the piece that are salvageable-parts that have a grain of truth in them or are kind of a “diamond in the rough,” as in, they could be revised to bring out the best aspects possible.
Focus on those parts, the parts you think are pretty good but could be reworked somehow, and edit those instead.
Then replace anything you think is utterly unsaveable-if you cannot find a single way to make it better, then just delete it and replace it with new writing.
If you save the good stuff and make it better, and get rid of the awful stuff, you’ll still end up with the basic structure of the piece you started with, which is nice.
Hope that helps!