Benign paroxysmal positional vertigo .
Ive had it myself twice from a blow to my head (caused by myself) that loosened the crystals in my inner ear , like you had happen.
The first time it happened I was turning over in bed one morning . I do this trick to lift the spread over me with my upmost leg and as the cover is up i spin from one side to the other .
I experienced a sensation of spinning over and over so badly I thought I would fly off the bed and slam the wall , and threw out my hands to protect myself . Opened my eyes and I was just where I should be, but on my other side . Very trippy feeling .
Later that morning taking a shower i bent down to wash my lower legs and feet and I thought I was turning somersaults like I had vaulted from a high dive and was spinning in the air head over heels . I snapped my eyes open and I was fine .
And thats when I figured it out . With my eyes closed I had the spins , with them open it didnt happen . Tested my theory with the toweling off , eyes open - fine , eyes closed - spins . The eyes grounded me . With them closed my actions allowed my inner ears to attempt to orient me in space with the crystals wreaking havoc on my proprioception .
It went away in a few weeks , returned months later for a short week , but i was prepared for it . Kept my eyes open for the situations that would trigger it . It has not returned for many years .
Sounds like you had a more severe case than mine . Hopefully you have resolved it .
✌🏻