Happened to me many years ago...but I lived and I launched into the wood with cruise control on at 55mph!
Wow, you owe your guardian angel, big time!!
I traveled as much as 75,000 to 100,00 miles a year in my factory rep job before I retired, most of it by automobile, and I saw a lot of wrecks caused by drivers falling asleep at the wheel. I only had one serious accident in all of those years and miles. I totaled an almost new Ford when it was overturned by a sudden freak gust of very high wind that also overturned a big tractor-trailer rig right behind me. I got a damaged cervical vertebra from being thrown violently into the roof, and was off the job for almost a year.
A seat belt would probably have kept me from injury in that accident. Ever since that time I have always buckled up any and every time I get into any vehicle, even if I'm just going to the Minit Mart for a jug of milk.
Ping! Sorry we are having a sad holiday season.
There was a young girl on Fox a few months ago that won some sort of Science award for a device she invented that will sound and wake up a driver if he/she falls asleep at the wheel.. I forget, now, exactly how it works, but she is supposed to be getting a patent on it so it wasn't a fly-by-night invention.