hi aiya, just read ur problem. honestly i hv not done any research or hv any scientific explanation for this but..err...just for some sharing.. i m a chinese and in m y family, there's a very old belief dat we (my family) when we were very young. i do not know whether this is a made-up story, a story to scare little kids or it's a passed down kinda belief. anyway, just to share.... my sister had ur experience before but only once in a very blue moon. from what i heard from her is: scientific explanation was she too stressed. non-scientific explanations were either she was sleeping directly under a spider on a web (a belief we had) or it's like wat u said spirit... for my family, we believe that if we sleep directly under a spider on a web, its shadow will make us feel an object directly laid on us which make us hard to breath n hence hard to move. honestly i do not hv such experience b4 n hence can't comment much n fyi, my sis did not find any spider on the ceiling directly above her bed. nonetheless, she changed her sleeping position, ie instead of laying flat on the bed facing the ceiling, she try to sleep sideways. the very last time she told me was dat she chanted religiously n the 'thing' left. somehow, i feel dat ur sleeping disorders shd b caused by ur stress n the sleeping position...hope u get well soon!