GBL keeps someone from falling asleep?

[Dr Who]

SWIM was trying GBL for the first time and took 1 ml about an hour before going to bed. However whenever they were drifting off to sleep they would awake with a sudden jolt. This was happening over and over again for hours.

I think awaking with a jolt in the first stages of sleep is fairly common and SWIM gets it occasionally (about once a month maybe) normally.

SWIM also did not get any euphoric effects, only a feeling that they described as a bit like being drunk but not as pleasant or relaxing. They also said it seemed to cause a ringing in the ears, slight headache and sensitivity to sound (i.e. sound seemed louder and irritating). Is it worth them continuing with GBL? Their primary reason for taking is to cut down on alcohol, and they thought that taking a dose of GBL when they had an alcohol craving (typically every 3-4 days when they would usually binge drink) would get rid of the craving.