Synonyms : badgering, bedevilment, torment

Example : Vigorous worrying finally loosened the saw.

Example : Distressing (or disturbing) news.
Lived in heroic if something distressful isolation.
A disturbing amount of crime.
A revelation that was most perturbing.
A new and troubling thought.
In a particularly worrisome predicament.
A worrying situation.
A worrying time.

Synonyms : distressful, distressing, disturbing, perturbing, troubling, worrisome