I've had my Betta fish for about 2 months now, and only recently has he started hiding under his plant at the bottom of the tank. He is in a 1 gallon circular tank and he eats twice a day. He will eat his food when i give it to him, but I've been noticing that he spits it back up soon after. He also has lost his coloring a lot and is becoming less vibrant than he used to be. What's wrong? What can I do to help him??