I had to stop riding a DF bike for nearly a year because of balance problems that cropped up after a cold. Nothing more alarming than quickly turning the head to look both ways at intersections and getting a dizzy spell while riding with cars passing you.
I invested in a recumbent trike, instead. Staying in the upright, slightly back position, while riding has helped a lot. I go a lot slower, but it's better than not riding at all.
The dizziness is not too bad now, when I get them, a quick little shake of the head actually stops the wooziness. The actual vertigo (very rare occurrences, thank goodness) brings on terrible panic attacks. For me, like it's the end of the universe, or something, not knowing which way is up.
The Epley maneuver looks promising. I tend to self-treat, once serious possibilities have been ruled out. The doctors covered by my insurance are rather clueless and only give me meds that cause more problems. Once they don't know what it is, or can't find anything serious, I go the self-treating route... I'd like to go back to riding a DF bike, though, for those times I want to combine a trip with the bus.