Just give him a lil time. if he is that stressed you should leave him alone for a week or 2 and then have 10-15 minute handling sessions with him. with frequent handling he should tame down soon. But for future referance most balls(snakes in general) are head shy so i wouldn't put your hand in front of his face whats so ever, especially if he is that nippy and nervous !!

Hope i helped

Brian