A lot of times airsickness "is in the head" and can be something that can be overcome, but not always. Ever met someone that put their mind to it and no longer was ticklish? I was never one to overcome airsickness but was able to minimize it's effect.
Some things that helped me where: Travel light, no big meals before flying. Personally, I always preferred dry heaves to wet ones--the taste, yuck! Avoid greasy and spicy foods, things that tend to agitate the GI system to begin with. Eat things with which your body is familiar. Try a few(!) saltine crackers, a little water and some flavored Tums. These last three items a put a little something in the stomach to give it "what it wants", help counter the gastric secretions (Tums in particuliar) that often pop up during airsickness, and gives me something to help quell hunger pangs. Try closing your eyes and relaxing if possible. Remove the visual component to airsickness when possible, maybe enroute to a pick-up. When possible, try to focus on the horizon. If it was bumpy going in, often times it'll be bumpy on the back out. Thing about taking dramamine while you're on the ground prepping the PT. Maybe you have enough time for the drug to take effect, 30 mins(?). Dramamine is a "downer", so keep that in mind.
Been where you are more times than I care to remember, 500' off the deck, 225 mph, 95+ degrees F, ,wet from the skin out, no airconditioning or air circulation, two hour low-level run-in, and no windows in a C-130. Not fun... good luck.