Aeronausiphobia is a bad companion, because it may cover symptoms of real airsickness. Motion- and Airsickness is thought to be related to histamine and the easiest way to treat is get vitamin C. A very good friend got a grip on his aeronausiphobia with chewing Acerola-C, which is also not influencing your airworthiness. Cheap, easy to get and I heard a lot of good things.