I was just wondering what is the most bothersome or debilitating symptom of MAV for others.
For me, it’s the motion-sickness/nausea I get. When that happens, I’m incapacitated until meds help. The migraine headache pain is debilitating, too, but I don’t get severe pain often. The feeling like I’m on a ship doesn’t always make me motion-sick, so it really doesn’t bother me unless/until it makes me have nausea. Sometimes I just laugh at it, in amazement that I have that feeling when being still.
It’s all pretty awful - but the worst, for me, was the exhaustion.
I agree with marie-johanne. All symptoms have a debilitating aspect. For me it is also the fatigue that seems to be the most consistently overwhelming.
I was at the pharmacy tonight and there was one customer in line ahead of me. I was having the hardest time just standing waiting my turn. I thought it would be great to have chairs or cots everywhere in public so I could be out and about in comfort! 
For me its the 24/7 imbalance and visual motion.Inside and outside never stops moving. Everyday is a test of physical and mental endurance. Those are the worst of another ten different symptoms that come with this thing.
Here’s a recent poll on this subject: http://mvertigo.cloudapp.net/t/what-is-the-toughest-symptom-for-you/1484