This doesn't look like a typical swimbladder issue to me (which would usually involve the fish trying to maintain depth by swimming downward, against buoyancy), but rather more like a possible spinal injury. Due to their swift movements and devil-may-care reactions to threats, fairy wrasses are prone to bashing into things - glass, canopies, corals, the surface . . .
Spinal injuries do sometimes recover - but sometimes they don't. I don't think there's much to be done, other than wait it out.
~Bruce, sad to see such an injury in a tank so full of beautiful, healthy, well-cared-for fish