I had the majority of my vertigo attacks long before my feet
"went". (the hypo thyroid seemed to really kick in at around 30).
I am almost 62 now.

I had two within 2 yrs of delivering my son. One was triggered by a test I had 2 mons after delivery. They gave me 4mg of dexamethasone to measure my adrenal functions, and the day after that I had a huge vertigo attack. That one was a real bummer with a preemie to take care of.

The one connected to Glucophage lasted almost 6mos...the worst was in the first week. It took me a while to link it to the drug, and once I ended it --the dizziness slowly went away.

Sometimes at night now I get dizzy in bed. I often wonder if that is my blood pressure medication? (I take it at night).
But that terrible vertigo, where you cannot even walk I haven't had now in several years...knock on wood!

I never connected my ear problems to neuropathy. But I suppose there may be some connection because of the hypothyroid issue which also causes PN.

So I wish you luck...it is just very hard to isolate things medically sometimes.