what are your readings for ammonia and nitrites and nitrates and also ph plus what kind of medicine do you have your fish in right now. I dont know if you have ever heard of this kind of medicine for bettas but it is called betta max it does wonders for bettas it has everything in it that they need including meth, blue which is for fungus You know how ragged and stuff thier fins look like when you first buy them from being kept in a cup. 2 days in that medicine and they look like you have raised them your self. Welcome to the forum and I hope your fish gets ok to. These people here are great they sure have helped me save my fish I havent losed not one due to illness I had one to jump out of the tank and die but that is it.