I've had this problem for going on 3 years now. It started when I took some anti-depressants (Valdoxam) for the high anxiety levels I was experiencing (prior to that I'd never taken prescription medication).
My body didn't respond well to the meds, I threw up all night, had severe shaking & when I tried to go back to sleep, this began (I didn't sleep for nearly 3 days straight & was in Emergency wards every night seeking answers. Finally a GP gave me Valium which got me to sleep).
It's all the same symptoms mentioned, jolting awake suddenly, being confused etc. I have it to varying degrees, sometimes horrible, lately I find I can talk myself into being calm through it & deep breathing helps.
Here's the other thing, I can't fall asleep unless my neck is arched upwards. I've wondered about vertigo but don't experience in daytime. My head has to be lying sideways on a pillow & chin right up otherwise I get an unpleasant dizzy, unbalanced feeling.
Things I've found that trigger this sleep condition for me are;
1. Alcohol
2. Over tired / under tired
3. Rigorous exercise, particularly late in the day
4. Drugs with a quickening agent i.e panadol rapid or nurofen plus
5. STRESS
Sometimes Valium has been helpful, sometimes not. The last 3 new guts in a row I've had this & Valium has helped me stay calm, but not stopped the occurance.
A couple of years ago when I was experiencing panic attacks, I saw a doctor who checked out my blood & found out I was high in cortisol & deficient in other things like magnesium l. She put me on a cocktail of vitamins & natural supplements to help with the panic attacks, but strangely this never occurred during the year I was taking these. I am going back to her this week to have everything checked out & hopefully find a solution. It is so challenging living with this mysterious condition, prayers & hugsfor you all until we find our solutions .. :-)