One of my lovely students, Caitlin, sent this to me, to remind me that what looks simple to teachers and examiners when we put up a piece of sight reading looks totally different to the poor student standing in front of it!  But I can assure you from my own personal experience that sight reading, like everything else in life, only gets easier with regular practice.  The challenge is to overcome the panic, tackle the music in manageable chunks and look for the patterns in the music.