My Betta has a problem (PLEASE help)
Okay, so I bought my boy Roderich about 6 months ago (in May) from a nice little pet store. He's in a neat little tank, 1/2 gallon and very pretty, zen-like. I know it's not too big but he's my only betta and the people I bought him from said it'd be fine. Up until recently, I fed him about 6 little food pellets (more like little tiny little balls, but that's what I was advised to use) a day. That could have been overfeeding, but it was 2 in the morning, 2 afternoon, 2 at night before bed, and he would gobble it up. I never changed his food or anything like that. I would change his water and clean out the tank once a week and usually on the same day although occasionally I would miss a day.
He was fine until late October when I noticed that he was acting very lazy and not going anywhere, just kind of floating around the top or bottom of his tank. He suddenly stopped eating or he would spit out his food. In the past month of November, he's eaten at most 3 pellets.
I clean his water once a week, still, and try to get him to eat, but when he doesn't eat, I spoon out the food so that it doesn't rot and make him sick.
I was worried about sicknesses, so I looked up betta diseases and it didn't look like he had any symptoms at all! I chalked it up to their explanation of "betta depression" but their only solution was to put him in a little space near his siblings, but I don't see how that would be possible since I bought him in one of those little plastic jars all by himself. In an attempt to cure his "depression", I even sprinkled in some freeze-dried blood worms, but he didn't even look at them (I thought bettas LOVED those things!)
After reading about the importance of water temperature, I tried taking my betta out of my room and, after changing his water, putting him in a somewhat brighter and warmer place on the living room coffee table, but when I was observing him more closely, he appeared to have a kind of white fuzz over his body. When I transfered him back to the tank, it had been dead skin (I assume) because when he moved, it peeled away and my boy looked as normal as he usually did.
PLEASE help me. I don't understand anything that could be wrong with him. I feel like his water is pretty consistently cleaned, I attempt to feed him as best I can (though he won't eat), but is he just sad? I don't want him to starve!
He looks much more dull and colorless than when I bought him, but at least since I changed the water temperature he's moving around a little more. But his fins are lifeless and limp, not spread out like a fan and he sits at the bottom with the black rocks in his tank. There isn't a plant in the tank, could that be the problem? Please help me, I really want to help my boy out. Thank you so much.