Lyin:
You may be suffering from a type of panic disorder I had most of my attacks while almost asleep, same symptoms except I would get really bad vertigo and feel as if I was dying. No elevator though, just on the way to rem sleep it would happen. It got so bad I actually was able to sit up in REM sleep (had a sleep study) it freaked the technician out because you are supposed to not be able to move in REM LOL Well, proved that theory wrong didn I LOL If you wanna talk more about it email me!