Again, id suggest looking up Sleep paralysis.
Aside from it will leave you paralyzed for X amount of time (seconds to minutes)- It can give you hallucinations. It can bring about a sense of fear that someone is looking at you from a angle you cant see.
In this state you can only move your eyes and nothing else. You cant speak.
A other thing, which kinda sounds like you described. . . Is a sense of adrenalin source traveling through your body.
this might be cause by a other factor to Sleep paralysis. . . .
To cut it short. Sleep paralysis is an abnormality in your brain (now dont be scared, its harmless and only messes up your sleep)-
but it will be in conflict about what state your body is in.
So youll be awake, while your body is sleeping. and you will dream while you are still conscious.
Now a question.
When you fall sleep "normally" how does it feel? It doesnt does it?
You feel tired, and maybe you just wake up suddenly in the morning cause you didnt even notice you where about to sleep-
Or you feel tired, close your eyes. . . and for a long time you feel. . . Soon. . .Soon ill fall asleep. . . . but you never notice when you do,.
Now imagine being able to feel the stage between being awake and asleep. . . Can you imagine what such an experience must feel like.
It must be terrible.
Youll lay down. Close your eyes. . . then feel your about to fall asleep. . . .
THEN- you start feeling your body shutting down while your still aware. Its going into sleep mode while your still conscious and aware of your own thoughts. ''
Well thats scary if you ask me. And that would jolt me- And it does. Happens often to me.
Actually it happens to may people. And ive provided an answer to another thread in this forum ill link to-
http://www.medhelp.org/posts/Anxiety/Adrenaline-rush-when-trying-to-fall-asleep/show/415706?personal_page_id=2145002#post_6878478
Just look at the last post- for my reference. Other wise read the others- They have some similar experience.
Of course im not saying "THIS IS IT"- But sounds like it might be.- And its scary as hell.
I woken up with the covers (from the blanket) over my head. . Had a hard time breathing and could move my body so i could remove it.... until i felt i was gonna suffocate and i ripped it away from my head.
I woken up to see a person standing in my room, who then ran over to my bed to attack me.
And ive had a night where i "woke up" 9 times right after i fall asleep due to what i simply think is adrenalin from me noticing my own body shutdown for sleep mode.
But yeah look it up-
In old days this event was chained together with a spiritual monster or an old lady who would sit on your chest, taking your breath away.
People now suspect it to be of course the sleep paralysis kicking in. + that sometimes laying on your back for long will add pressure to your muscles and lungs making it harder to breath due to your state of paralysis. (remember your whole body is paralyzed- if it lays in bad position, you cant change it before you get ouy of the paralysis,. )
Well done here. Dont take my word for a doctors. There are other things that could make you short of breath while sleeping.
But Ive researched this quite a bit since im a victim to it myself.
Any questions concerning it, well feel free to ask. Other wise good luck with it.