Since last year, I have difficulty being a passenger in a car or an airplane and the problem is getting worst to the extent that the last time I tried going long distance in a public vehicle, I had to ask the driver to stop after just a kilometer. The moment a vehicle starts accelerating (around 55kph) and the vehicle starts swaying a bit, my head starts (for lack of a better word) spinning and I am unable to think straight. This is followed by panicking, and palpitation. Even in planes, when there is turbulence in air, or even the swaying in the runway, my brain gets scrambled. I've tested myself on roads and the problem is almost absent when the road is very smooth and the vehicle does not sway or gets jumpy. I've read up and I think it's not just psychology. Maybe related to ears/nerves and my sense of balance?