Guys, I have this weird problem maybe many others have too

Whenever I drive my car, I never get car sick but when I enter into a different car- that is any car mostly, I get a pain in my head immediately when I get in the car- its like the instant i get in there, the pain gradually gets worse

I don't know if its because of the smell of the car or I don't like the car's surrounding environment, but mostly I roll down the windows and let fresh air so I can get my head to cool down

It's been getting better of late, but what are some suggestions to cure this in the future?