Have had that experience before. Also, would be really tired and fall asleep only to awake in about an hour and not be able to go back to sleep.
My problem was finally diagnosed as sleep apnea. You fall asleep and your air passages relax too much and your brain tells you that you are smothering. Hence, the adrenaline rush and not being able to fall back asleep. If anyone reading this has ever had it happen to them and feel tired all the time, I suggest that you get your doctor to prescribe a sleep test to determine what the cause is. It can be a life or death situation.
I understand. After several years of maybe three or four times each week. I would wake up screaming bloody murder. Scared me my wife and the kids. It went on so long that nobody woke up or heard me. I was later diagnosed with sleep apnea. Had one time that I was awake and could not move.