Could the white spots above the water line be remnants from the tablets? I'm certainly no expert and have just started out, but when I gave my gold fish fluke tablets, some of the un dissolved medicine gathered above the water line.
As to the health if your little guy, I'll leave that to the experts. But I know they always ask for tank size and water parameters (do you have a liquid test kit?). If you posted that info now, they will be able to assist you more quickly.
Good luck and I hope the little guy gets better soon, R