AynaDee, My nighttime wakeup emergencies were very much like yours, except that my trigger to wake up was the sharp pain in the middle of the abdomen. Actually the pain was in the area of the diaphragm, where we breathe. I think my events were also triggered by something in the Central Nervous System failing to signal me to breathe, so that then I had this acute pain which MADE me wake up.
During the more severe of these episodes I would say to my husband, before I was fully awake, "I have died." or "I am dead." I didn't say "I'm dying". I WAS dead, in the opinion of my body. sometimes this would be so extreme that I would throw myself out of the bed and somehow end up against the wall a few feet away.
The Central Nervous system being damaged is a problem! I don't have this type of pain signaling any more at night. Maybe because older people sleep lighter than younger ones. Maybe I do not go into that very deep sleep now.