The OP stated;
Last night I noticed long white worm like poop coming out. They seem to be dead white worms.
In which case his fish appears to be suffering from worms, most likely a tapeworm, which would require a deworming agent such as PraziPro aka Praziquantel. For nematodes (round worms) you're better off treating with levamisole as per the directions in the following link.
https://edis.ifas.ufl.edu/fa091
Neither metronidazole or epsom salt will cure a fish that's infested with worms. Epsom salt can act as a purgitive agent and help flush the worms out, but it won't kill the worms, or their eggs.
Once the fish is clean of worms I would wait & see before taking a shotgun approach with medications designed to treat internal pathogens such as Spironucleus vortens, aka hexamita.
The white poop isnt actually a worm but its his intestine line shedding.
If that was the case what you would generally be seeing is clear poop, not white.
Also keep in mind that almost all fish medications have the potential to be dangerous and/or toxic at high enough dosage rates, or if used excessively. The vast majority of fish that hobbyists on MFK keep in captivity, such as flowerhorn, have absolutely no data to support the safety of any of these medications, at any dosage rate. These medications generally do not take into account the age, size, or weight, of the fish either. Certainly many of these aquatic marketed medications work, and are better than watching a fish suffer, and then die - but that sure as hell doesn't mean that any of them are 100% "safe", either, at any dosage rate. My advice has always been that unless your fish is already knocking on heavens door, start small & work your way up, not the other way around.
Good luck.