I am in the same situation. I know that flying is safer than riding my motorcycle but that doesn't really help me much.

The one item that has helped me the most is to pay attention to the amount of vibration and 'turbulence' I experience on the bus and in a car. I close my eyes and pretend that I am on a plane and I am comfortable because it's a familiar vehicle. Then when I get on an airplane I close my eyes and imagine myself in a car whose turbulence I have a much higher tolerance for. This helps me for low to medium turbulence but not for high but it might be a starting point.