hey.. a practical thread finally, not the usual pish about modular vs integrated..
usually started by people with zero hours.
I was the same - First lesson, felt terribly unwell. Thought it was the end of my piloting dream but decided to try again. It got better every time. As you proceed, your body gets used to it. Also, the busier you get, the less time you have to think about it. When you start doing most of the handling, it gets even easier. Usually motion sickness develops when you're not in control or you're just a passenger.
I have 30 hours now and no problems at all, glad I didn't let the first flight put me off. Just keep your eyes away from the instruments as much as you can and try not to let too much time pass before your next flight !
Hope it's of any help