Woof etc.
Yes. An asymmetric blockage is I suggest not that uncommon. Can be v nasty re vertigo as you suggest. Therefore the emphasis has to be on prevention before things gets to that stage.
Don't know if you are civil or mil but the situation in the 50/60s with unpressurised militay aircraft charging up and down from SL to 40k quite quickly meant you never delayed in clearing your ears when descending - if exagerated throat swallowing action did not do the business you pinched your nose and blew pretty hard there and then - long before any pain or other symptoms were experienced.
When pressurisation became the norm things were a little easier but the problem was still there lurking for the unwary.
If you are on your own you can always climb back up a bit to try and get the tubes open again that way.
If in a pressurised fast jet descending short of fuel you get a blockage (sinus or ears) then I used to blip the presusurisation off to get the cabin to climb for a moment while I got stuck in with nose pinched and blowing. If the sudden repressurisation became a problem then it had to go off again until I was down.
As ever lots of ways to skin a cat but you soon learn what suits you and/or gives you problems. A nasal spray is the answer for a bad sinus block but as has been said earlier can have a rebound later although these days the beneficial ffects can persist for several hours rather than 20 mins as with the spray in the old days.
Going right back to WWII the Luftwaffe pros on the Me163 used to pierce their ear drums and fit little grommets. End of problem. Of course that did nothing for hearing in old age or keeping bugs out of the inner ear. A matter of priorities I guess!
JF