I’m pretty new to VR. My initial sessions had me feeling like throwing up after 10 minutes. I found that starting off, seated games were better than FPS types (although it was hard to limit my time in Into The Radius!). From there I started short sessions of standing type games and the moment I started to feel slightly woozy, I’d stop and take a decent break (a couple of hours). I’ve been able to slowly build up a tolerance that now, after a month, I can spend an hour + in game and only feel a tiny bit uncomfortable.

For me, I think the trick was to stop well before you get sick. If you get to that point every time then I really think your brain simply starts associating VR with sickness. Stopping before that point negates this (for me at least).