Aww.. poor baby.
Before doing anything, keep in mind that when you see pine coning, that is usually a sign their internal organs are shutting down, and sadly, it's not too common for them to regain health after they get to that point. But, it's still very much worth it to do as much as you can to save him! Kudos to you for wanting to give him your all!
Go ahead and do 1 tsp per gallon of the Epsom.. it's gentle and 1 tsp isn't a whole lot, nor too much for him to handle. Daily 100% water changes as well.. hopefully within a week to 10 days you will start seeing a difference in him.
I am unsure about when to cut down on the food intake.. I would ask in the breeding section, or PM a breeder such as OFL who would know when it is best to change their diets.
I wish you and the little one luck.. hoping for a full and speedy recovery!