DO NOT WORRY its normal!
Ok here's the thing, whenever I fly as a passenger without being at the controls, I instantly get SICK.
Last year I went to Africa to work, during my first flights I flew as a passenger with the base manager, we were always very low level, manuvering like I didn't think a helicopter could ever perform. I would last approximately 30 seconds without being sick, I would sometimes stay on the ground because of being soo sick, the base manager has been training pilots for 20 years to do this job, and he's told me it is quite common for this to happen.
One thing that helped me, was looking at a where the helicopter is going to anticipate where the helicopter would go next, this helped a lot! Its not the same having the helicopter bank suddenly 60 degrees right as you are looking at a monkey on a tree abeam you, than looking forward and knowing which way its going to turn next.