There's an FOV setting in graphics options. ... But (as another person with motion sickness) I'd love it if I could increase it FURTHER, or push the camera a little bit further back.
You could always try playing windowed, with a small window. The whole point is to keep the window far from your face. If your playing on the deck, try to keep the screen as far from your face as possible.
Take breaks, not just because you should, but also to just eat. When I'm hungry/weaker, I'm more susceptible.
Or try taking a bonine pill in the morning before you play. The only side effect I get from them is they make me a little sleepy.