I have a 5 week old betta fry, he is over half an inch and has been doing well until now. He keeps on sinking, he shoots up to the top for air then will sink back down. When he tries to swim he only declines back to the bottom. He stays on the bottom or sometimes lays on the heater or filter, sideways and gasping it seems. What do I do?! I feed my fish and none of the other have problems like this. I feed the fry microworms, baby brine shrimp (freshly hatched within 12 hours) and some atison’s betta starter. he is my biggest fish and I’m really worried about him. Help!