55 Gallon Tank, Various Plants and Fish, Low Light (less than 1 Watt per gallon)
Change water and don't give up
2 Golden Rams, 2 German Rams, 1 Rainbow Shark, 1 Flying Fox, 1 Bristlenose Pleco, 1 Salfin Pleco, Panda Tetras, Neon Tetras, Red-Blue Columbian Tetras, Serpae Tetras, Black Neon Tetras, and Glo-Lite Tetras
Various Plants, Anubias
When you see signs of stress in your fish, you can then take steps to identify the source of that stress and then to resolve it before it becomes a major issue.
If you're looking for a unique way to stock your new tank, give freshwater shrimp a try.
If your fish is suffering, you may want to consider euthanasia as an option to humanely end his pain.