My Mercutio has been very ill for a few days now. I did a water change about 3 days ago, and I noticed after, he had a weird twitch. He would just sit at the bottom of the tank and twitch and sometimes bolt across the tank. Then he began to just stay at the bottom of the tank. On his side. He has been like this for a few days now. I have done lots of research and checked for ich or velvet. No signs. He's not active or eating. He lives in a 5 gallon tank, filter, heater, live plants etc. I am really at a loss here. It's actually stressing me out because I cannot figure out what to do. Not sure if I can add a photo, but some of his fins do appear to be jagged/broken off.