We have had lots of rain and a water main break the morning that i noticed strange behavior. Two days ago our water went from rust colored, to piss colored, to white, and now back to normal.
Did everyone else miss this?
Without any doubt in my mind, that is what triggered your problems. I'm an old fart and have seen water main breaks wipe out entire tanks of fish, several times over the years, when a hobbyist didn't realize that their tap water quality was not normal. When a water main is repaired all sorts of toxic metals etc can get stirred up into the water line, and my advice is to NEVER perform a water change in your tank until at least 24 hrs have passed since the repair, longer if the water quality doesn't seem like it's back to normal. Some of the crud kicked up from a water main repair will make a small spike in ammonia seem like a trip to Disneyland for a fish!
With regards to ammonia, the OP stated;
I tested before a water change but after dropping in dozens of night crawlers.
.......... which can easily cause a small, but temporary, spike in ammonia - in anyones tank.
As far as nitrates, while I doubt they are the cause, the nitrates could be a LOT lower, and the high levels certainly add to stress levels in most fish. If the water lines have cleared up, start daily water changes and watch for improvement. I would personally not add Melafix, or even salt at this point. Focus on improving water quality, add carbon if need be, most toxic elements aren't easy to test for.
Good luck.