Flying in a US based major commercial flight is essentially the safest form of transit there is. The “scariness” factor and the seriousness which which aviation incidents are treated wildly inflates the impression of danger. You are more likely to be injured driving to the airport than on the plane.
Also, the air in a plane is mostly not recycled, most of it is fed from compressed outside air brought in via the engines (before fuel is added obviously), the air that is recycled is HEPA filtered and won’t get you sick.
It is frightening how many people believe that they are being safer by driving instead of flying. Driving is among the most dangerous common forms of transportation, the illusion that you have control over your safety in a car unlike a plane is warping your perspective. You are hundreds of times more likely per mile to die in a car accident than a major carrier US based flight.