MarkG
Airsickness/seasickness is usually an indication of a person's significant sensitivity to small accelerations. Without such sensitivity you would't get sick and some medications are available which serve to reduce your sensitivity.
Now, for a pilot, do we need sensitivity to accelerations. The better pilots certainly DO. For other crew members the opposite prevails.
Rejection of potential pilots by Air Forces because of a propensity to airsickness is a terrible left over from WW2 when the system was unconcerned with producing pilots with above average stick and rudder finesse. The "system" was more concerned in simplifying an aircrew production line.
Most above average 'stick and rudder' pilots today will be reluctant to admit to a so called "weak stomach". But it is their inherent fundamental reason for becoming above average. Those that aren't prone to airsickness don't appreciate their reduced sensitivity to the motions of an aicraft and compensate as best they can.
The pilot having enhanced sensitivity to motions will have no problems if he himself is in control of those motions and be less comfortable when someone else is in control.
I am in that category.
Having been through an extremely wide range of aviation experience including instruction and experimental flight testing, I would choose you as a potential above average military pilot were I on your selection board.