The loop that keeps it going

What started your bad sleep is often long gone. Something else keeps it going, and it is a loop. Go round it once.

A stretch of badnightsCompensatingThe bed stopsmeaning sleepEffort and clockwatchingDread at bedtime
Whatever started this has usually gone. The loop is what keeps it running, and the loop is the changeable part. The diagram shows a loop running through: A stretch of bad nights, then Compensating, then The bed stops meaning sleep, then Effort and clock watching, then Dread at bedtime.