>>310487740
It takes training. I got some tips:
>only do small sessions at a time
>take regular breaks
>remember to breathe. You would be surprised how easy it is to stop breathing properly when the headset presses on your nose. You dont have to force it, just remember to take a deep breath in now and again
>you will get sick a couple times if you do, stop immediately and go rest and maybe get some fresh air. 
>rely on limited view, low movement games at first. Fixed turning is good. 
Eventually you'll be able to VR a couple hours at a time with regular breaks like I can. I COULD easily go under longer, but its good to have regular breaks playing any game.