It's not that bad.
You come on the plane prepared by preparing years before the kid ever gets on the flight. If there are real physiological issues (not ones induced by lack of parenting) then you need to speak to your doctor to see what he might be able to prescribe. If there is nothing that can be done then you simply don't fly. Not fair to other passengers.
I have had tiny babies screaming on flights. It is not their fault because of the air pressure changes on their ears. It can be uncomfortable and scary for them. But none of that makes it any more pleasant for the other passengers.