Ball means constipation. It's okay that it's not so ballish anymore.
I would look for a different pellet to feed him, because Hikari are full of wheat and fillters.. depending on the one you have it's either primarily fish meal (fish byproducts.. think McDonald's Chicken Nuggets) or wheat which is the worst. A good quality pellet should have the first two or three ingredients as whole
fish. If you can find New Life Spectrum Betta you can feed 5-8 split up into two smaller meals and one fast day a week. Since he has been on so few (2 is really minimum and pretty low) I would start lower at 4-5 and see how he does then think about adding more if he stays regular.
Sounds like Ich actually. I'd start with that.. salt at 1 tsp per gallon predissolved and increase temp slowly to the 86-88 range with one degree per hour and no more than 5 degrees per day. Leave the temp this high a week past the last sign of ick and the salt can be used up to 10 days then you will need to do a series of water changes to remove it.
I'd also be looking for ways to boost his immune system by vitachem, or IAL, or getting some garlic guard or fresh organic garlic and crushing it and soaking his pellets for 10minutes in the garlic juices.
Maracyn 2 will not work for internal infections.