... it's good to just save that original file that you've thrown the kitchen sink at, close it and start over as a new song and name it SamesongTest2 or something.
I do of course normally do that and I also have an automated backup system that keeps files for many months, so it's rare for me to lose anything. In the case of this particulay song, the alternative that I have sounds better anyway, so I shalln't bother to recover the broken one.
I normally keep untouched originals, often with just .bk appended, but my auto-backup is a dedicated machine in the lost above my garage. It copies all work data from my fileserver overnight, every night, keeping a trail of changes over those months, so I can recover copies from various historic dates if I need. I've had if for years and I doubt I restored more than a couple of dozen files of thet time ... but I can if I must and that's both a comfort and, on those few occasions, a Godsend.