Popular singer Arijit Singh seems very upset, and his Facebook page posts stand witness to the mental and emotional turmoil he’s going through. Going by the two recent posts by the Tum Hi Ho artiste, all is not right between crew members of the much-awaited Salman Khan-starrer Sultan. Speculations have been rife about Arijit – who has sung a song for Salman in Sultan – having rubbed the superstar the wrong way at a gala music programme. Now, confirming the rumours, a worried Arijit posted a heartfelt letter on his Facebook profile, pleading Salman to retain the song sung by him in Sultan.