I've experienced anxiety and insomnia on and off for most of my life, I'm just a high energy, high stress person. I can usually manage it with exercise and deep breathing. However, I had this experience back in college during periods of peak stress, and I've starting experiencing it again. For the latest experience, I recently went 5 nights getting ~3 hours of interrupted sleep per night at most. By Day 6, I starting having horrible pain in my brain (not like a headache, but what felt like deterioration or failure). When I attempted to go to bed that night, as I was drifting off, I had a sensation, with absolute certainty, that my brain was shutting down and I was dying. It felt kind of like a computer crash that just fails. I immediately fought sleep to struggle against it, but I then had trouble with basic functions after (opening my eyes, seeing, moving my limbs, breathing) for at least 30 seconds to a minute. It happened again a couple of times that night before I was able to finally fall asleep. It's such an awful, scary, final feeling, I literally thought I was going to die. Has anyone else experienced these exact symptoms?