Hi Bruno,
I'm sure you will be OK. I have never been a good traveller, used to be continually carsick as child and was sick on my first flight in a Chipmunk. I have done a lot of serious sailing and I have always had to be careful if going down below.
I have only felt sick twice as a pilot in 250 hours power and about the same gliding. Once was doing continuous tight turns and the other was soaring in a very robust thermal. In both circumstances I could stop the process and recover or, in the glider case, land fairly promptly. I can now usually manage about 10 minutes of well flown aerobatics (not by me) before I start to feel the cold sweats.