This word in part relates to the breed of dog the whippet, a racing dog that is very fast, hence 'whip'. 'Disery' is a mix of the two words dizzy and Dysentry. 'dizzy' because of dizzyness and Dysentry because of the symptons of dysentry: abdominal cramps, fever and rectal pain.
The word is used to describe a job, that is too hectic, fast and stressful and basically spins you out and would be a 'pain in the ass'. Hence it is always used in a Derogotry way.
Charle's i know the jobs good pay, but that place is a fucking whipdisery