A few weeks ago my goldfish had a red spot on his head and I looked it up and thought it was an anemia burn, and I was in the process of moving him from a normal bowl to a 1 gallon filtered tank, and after a few days it went away. Now its about 3 weeks later and this morning I noticed a spot again except its like a dark brown or light black, plus his tail has dark streaks. And most things online say thats a sign that the fish is getting better? But he's acting strange and the pet store said it just may be him changing colors since their spots and not bumps, I'm very worried cause now hes just sitting at the bottom of his tank not moving and hes usually spastic. I went to tap it and he usually gets right back up but now he just like moves to another spot to just lie down. I'm really worried so if someone could tell me if hes sick or anything and what to do! I'm going to change his water right now but if theres something else I could do I'll do it asap cause I'm afraid hes dying! Thanks for any help!