Concerned and mindful, but not panicked. Do a large water change, but no tank maintenance. Meaning just do the water water change wo cleaning the substrate, etc.
Offer the fish garlic soaked foods. What are you feeding the fish now? These fish are grazers and need to have all day grazing opportunities in the aquaria. When soaking the food, get very nutritious foods. Or offer up the fish's favorite. There is a frozen sponge product sold within the hobby as fish food that the fish might like. Feed him well, and every meal garlic soak the food.