You might find it worthwhile to be examined by a specialist in aviation medicine. The conditions you describe are replicated by a session in what is called the "Barony Chair". It is used to screen pilot candidates, and to demonstrate that sensations do not always correspond to reality for instrument pilots.
Hi,
Vertigo (things moving around you) can be a symptom of inner ear disease where as non specific symptoms such as light-headedness, unsteadiness, motion intolerance may be due to CNS, cardiovascular, or systemic diseases.
You should consult your doctor to get the blood pressure checked and an ear examination.
Regards.
In most people this problem is caused by turning their head. I put in a lot of time doing aerobatics in airplanes and if I turn your head to the side in the slightest, it's inner ear city. That's why children get sick on commercial aircraft. They "rubberneck" while the aircraft is banking. Of course, then again it could be space aliens.