I've had my fancy goldfish for 2 years and he has suddenly gotten really ill. I keep him in a 10 gallon tank with gravel and another small tetra fish. I noticed yesterday that he would couldn't swim up and would remain on his side. His tail and dorsal fins have red veins on it and appears to be thinning on the end which I assume is fin rot. I noticed white build up on him and immediately thought it was the ich, so I used a method that has worked in the past by using garlic to raise their immune system and cleanse the water. I left it like that for a day then realized my misdiagnosis and thoroughly cleaned the tank and put him back in. He is still not swimming but the white build up on him is gone. His fins still have the rot, and the red veins as well. I did notice that he won't open his mouth, he's not his usual, mouth always moving and eat anything that moves, self. I waved a piece of garlic in front of his mouth to eat and spent 20 minutes trying to get him to pay attention but he didn't move at all and seemed completely disinterested. I'm really worried, help please. Here are some pictures of him just sitting after I thoroughly cleaned it.