Mark G,
I used to get as sick as a dog when I began studying for my PPL.
The sickness would come on quite suddenly and it was very debilitating - I couldn't control the aeroplane in that state.
I really felt like quitting and it was very depressing. I used an ordinary commercial airsickness tablet called 'Stugeron'. This is a drowsy drug, but since I was with an instructor, I felt that it was OK to use it.
At first I used it all of the time but gradually I weaned myself off it, only taking it on blustery days, but now I don't take it at all.
Is your airsickness related aerobatics or just the ordinary sensations of flying? Are you nervous before going flying? Do you find the cockpit environment hot, noisy, cramped etc. ?
I am afraid that the only way to overcome this is through further flight training. It seems to me that you are a promising candidate for a career in the RNLAF and it would be a shame if they didn't give you another chance if you could prove you had overcome your airsickness.
Regards,
Noisy