Hi! I'm new and I just need a bit of help. I have had my betta for at least over a month now and he has very suddenly become lethargic and not eating. His mouth and gills have become discolored wnd he just looks beat up! I attached some pictures. There is almost gold scales around his mouth area. He is still swimming towards the top and pretty fast as he always is. I just really need help! I have a 2.5 gallon tank, heater, just bought a new great filter, plants, and a snail.