There's a device called the Otolith [0] that supposedly can cure vertigo and supposedly prevented motion sickness in VR, but they're only chasing the market for solving vertigo.
Curiously, what games are you playing? I find that games that involve real world motion didn't match virtual world motion (ie, any racing or flying game), I feel sick within seconds, but games where the two worlds always match (ie, Beat Saber, Pokerstars VR, Superhot VR, Space Pirate Trainer), I could play for literally HOURS and feel fine.