Had Benign Paroxysmal Vertigo a few years ago. It was bad enough to send me to the ER where they figured it out, and did the Epley maneuver. Felt better in a few hours and haven't (Dear God, KNOCK ON WOOD) had a recurrence. Hope it's something simple like that.
Chas R.

http://www.webmd.com/brain/tc/benign-paroxysmal-positional-vertigo-bppv-topic-overview

http://vertigotreatment.org/treatment-for-vertigo/epley-maneuver/