Hi, welcome to the forums, your symptoms are suggestive of rapid eye movement (
REM) related parasomnias involve the intrusion of the features of
REM sleep into wakefulness (eg, sleep paralysis). It is a type of sleep disorder.
Few of the individuals are known to suffer from parasomnias esp. when they are on non-benzodiazepine sedatives, drug abuse etc. otherwise no definitive cause exists in few individuals apart from stress, positive past history of abuse etc.