Extreme dizziness and nausea and lightheaded for almost 12 hours! what do i need to do?

BPPV vs Vertigo: Is it positional, ie more when you look or move one way.(right or left) if so, get on u tube and read about beinigh positional vertigo and do the exercise. If not, consider going to the er or at least call your doctor.

Consider ER/ENT: Vertigo of this duration is not positional as positional vertigo lasts less than 1min and is triggered by getting into or out of bed, turning over in bed, or flexing/extending head. Consider menieres especially if ear full, tinnitus, hearing loss. May be vestibular migraine if headache, sound/light sensitive. Vestibular neuritis which can last days to week. Stroke. Or labyrinthitis-vertigo n deaf.