Thank you for sharing. That sounded very similar to what happened to me. I figured I had slept too well and needed to wake up more and when i tried to stand, kept falling down several times luckily in the grass in my yard, and nothing broken. i too ended up in urgent care and was saw my ENT later who said what your care providers told me the same it was treatable with exercises which also worked for me after a few days similiar to what you did.
It is very scary I still have some dizziness but i also think i have a allergy and sinus infection that hopefully will go away soon as soon as weather changes again and things settle down. thanks again for sharing your story.