My betta had fungus twice. I treated him with Jungle Fungus Clear. I also totally cleaned out the tank two days ago, but kept 75% of the water. I boiled the fake rock, gravel, etc. He was fine until today. He has a small dent in his head. Half of it is kind of yellowish and the other half is the normal brownish blueish color of his head. HELP!!!! What's going on!!!!