Slightly off topic, but I can't play first person shooters--or, heck, even Minecraft--because I get motion sick from simulated motion with no actual motion. It's so bad that when I used to try to play, I'd continue to be sick if I watched, after I'd get sick and stop, someone play from across the room.

The odd thing is that I don't get seasick, which is (mostly) from actual motion with little, no, or confused apparent motion. Go figure.

It does get better with practice. Many small sessions are better than one long session. Take it off right when you feel sick and don't try to push through. Try these exercises to increase your tolerance: http://elevr.com/yoga-for-building-vr-tolerance/