Not sure what the medical rules are in the RAAF regarding use of motion sickness drugs/patches or what the current USAF rules are. But when I was going through aircraft commander upgrade training (B-52) my EW would always puke during low level. There's nothing like getting bounced around sitting backwards in a hot, windowless cubicle for 1.5-2 hours. If you were the least bit susceptible to motion sickness, the old BUFF would get you. Anyhow, the flt docs gave him this patch that you wear behind the ear. He never puked while wearing the patch and after only 3 or 4 rides with the patch, he could fly without it and had no problems ever again. This may be a possible course of action/treatment for your issues. Good luck!

Which brings up a good old radar navigator puking story/prank. Some of our crustier RNs were merciless on new navigator's during low level. One would prepare a thermos of cream of mushroom soup for a flight with a new nav. During low level when the nav wasn't looking, he would sneak a big swig of the soup and hold it in his mouth. Then he would get the nav's attention by "frantically" thrashing around searching for a barf bag. Naturally, he would "find" a barf bag just in the nick of time and "puke" into the bag. Then he would calmly just tip the bag up and drink his own "puke" in front of the new nav....This was usually followed by the nav frantically reaching for his barf bag....Oh, the good ol' days....