Yup, looks like popeye- can easily treat and not deadly unless left untreated for a long time.
Poor you and your little guy =(
Looks like you have Epsom Salt already, which is good since that is what you are needing. And luckily, you can use Epsom with your other medication if you choose to continue.
I would continue the 2tsp of Epsom, daily 100% water changes for the next week. If by the end of the week it's still there then I would combine the Epsom with either API Tetracycline, API Fungus Cure, API General Cure, API Triple Sulfa, OR Mardel’s Maracyn.
Poor fella.. question- are the white spots in the last pic on him or on the tank? Sometimes popeye happens when a fish has Ich. It can also happen by gas collecting in him (the "bends"), and even from hormones.
I would stop the medicine and just continue the Epsom for now, he may fair better, and heal better when his body isn't under the extra stress some medications cause. Epsom is very gentle and shouldn't stress him out.