For the last year or so i get very nauseous when swinging and when riding in a car. why is this? why a change? so i be concerned?

Nausea Sensation is: perceived within brain stem (not the body) & triggered by fear, feelings of insecurity (in dreaming level of mind), commonly from issues for which we avoid conscious awareness & choose to focus on other possible reasons/causes. All the available nausea medications work within the brain stem, within the "nausea center"; the "area postrema" of the medulla of the brain. Understanding is limited.