Sleep problems are issues with sleep deprivation that are often caused by emotional factors like stress, worry, anxiety or excitement. Environmental factors can also contribute to sleep problems. Not being able to sleep despite it being dark and quiet, with only the sound of a clock ticking in the background, exemplifies the frustration of dealing with a sleep problem.

1. sleep problem - noun a problem of sleep deprivation which is mainly caused by
emotional issues, such as stress, wordiness, anxiety, excitement or environment. -
(Dictionary of Team Create, Connect, Communicate, page 1)
I can't sleep; no light burns;
All round, darkness, irksome sleep.
Only the monotonous
Ticking of the clock