sounds like something else. Possibly a protozoan or bacterial infection in its brain. Do some daily partial (30-40%) water changes and gravel clean the tank. Make sure the filter is well maintained. It might clear up in good water quality but it might not. Medications don't always work on problems like this. You can try Waterlife Myxazin it might help but might not.
To work out the volume of water in the tank
measure Length x Width x Height in cm
divide by 1000
equals volume in litres
When measuring the height, measure from the top of the gravel to the top of the water level. If you have big rocks or driftwood in the tank, remove them before measuring the height.
Remove carbon from the filter before treating otherwise it will absorb the medication out of the water.
