Sudden Nausea as I fall asleep...

For a year now I have been plagued by nausea that accompanies the onset of sleep. I can go to bed feeling perfectly normal, no anxiety, no nausea, nothing. Then as soon as I drift off I am jolted awake by a pang of nausea. Over and over and over.

Has anyone experienced this before? My doctors have no idea what to do with me...

If the doctor's can't find anything, ask to be referred to a specialist. Did anything notable change for you a year ago?
Common things could be esophageal issues like GERD or acid-reflux. Sometimes I get that a few minutes after laying down. Much depends on what I eat or drink before going to bed.
A cold glass of seltzer will give that 'burp' of relief and I can go back to bed.
There was a time when I would get bed-spins. Especially after bouts of alcohol use. It was very disorienting and I would vomit before I could make it to a wastebasket in the dark.
There has to be an answer for this. Best of luck to you.