Unless there is bloating I'd skip the Epsom salts. Peas or brine shrimp will be fine.
If ammonia and ph are fine, I'd then dose the kanaplax. With the water changes, make sure the water is roughly temp matched and pour it in very slowly or pour it into a tall glass to baffle it so he doesn't get the force of it (for my betta I put in a seperate container and acclimatise back - that way I don't have to worry).