I have unfortunately lost several awesome super males to this exact thing (2 rhomboid and 1 lineatus). I was down at my tank and an hour later I come down and the fish wasn't swimming right (just as you described). Really stinks they are such skittish fish.
Bring salinity up to 1.025-1.026 and temperature between 77-78 degrees to start with.
Get a 2nd opinion on parameters by taking a water sample for testing to a trusted pet store to compare with your readings