I would not be feeding him at this point. He is bloated and shouldn't be fed right now until it goes away, unless you're feeding medicated pellets. He needs to be in pure 100% Epsom salts with no perfumes or additives ASAP. I would start with 1/4 tsp per gallon, predissolved and work him up to 1 tsp per gallon. I would also pick up some Seachem garlic guard, Hikari betta pellets (not the best nutrition but great for soaking) and metronidazole by seachem. Put a small amount of the garlic guard in a cup or bowl, add one scoop of the metro, stir in pellets and let soak for 10-15min. Feed 2 twice a day. This will help with internal infection.
If you want to feed freeze-dried anything you need to presoak it or it leads to these problems, unfortunately . Some are more susceptible than others but it's a common problem. A lot of peopel won't feed freeze dried anything for that reason, but you really need to be soaking if you want to. Otherwise I suggest a good pellet like NLS betta. You can feed 5-7 or so a day. They also contain garlic which acts as a very nice preventative against internal infections.