Hello Welcome to HCM Your symptoms of dizziness, blackouts, fainting, nausea suggest vertigo. This problem could be due to many reasons like inner ear disease (ear has balancing apparatus called semilunar canals) or may be due to migraines, seizures etc. Usually following viral infections causing viral labrynthitis (inner ear disease) or benign postural vertigo are usually benign which require consultation with a Ear specialist but difficult problems like migraines have to be evaluated by a Neurologist. You could better consult either of the specialists and get evalauated as soon as possible. Wish u healthy life.