I was in a very similar situation! But in my case, it went away as I grew older. It was a significant relief to me when one of my aunts explained that she was the same way when she was a kid, and it went away as she grew older. So I hoped the same would happen to me, and it did. In my case, the motion sickness was the same whether it was road, plane, or a banana sea boat ride. I would start vomiting, everything would turn, it was a horrible feeling. I used anti-motion sickness pills when I was traveling by plane, since you can't just get off the plane! That was when I was studying abroad: I had solved my car sickness issues, but still had the plane issues. Now I don't have those either. But I'm still more sensitive than most people: I still can't handle banana boat rides! Oh, the gym as well! I remember being sick (vomiting) after hard gym sessions!! Basically the solution is to get accustomed to it, to go slowly, not to increase exercise suddenly, and I think that's the solution to all of it, car or plane etc., it's somehow a matter of habit.