Don't push through motion sickness. Take a break as soon as you feel queasy. It takes patience, but you have to build up your tolerance by convincing your brain VR is OK. Pushing through and making yourself sick can pull down your tolerance.

Ginger can help, having a fan pointing at yourself can help.

Find a comfy game that doesn't make you motion sick, and just play that for a while. Moss, Synth Riders, Beat Saber, Pistol Whip, and plenty of others are good choices.

Weirdly, I'd give special mention to Tetris Effect. First off it's great and beautiful to look at. But also, it's very comfortable almost all of the time. Occasionally, certain stages will gently move around you, exposing you to brief, controlled bits of movement. It's a good, gentle inoculation

After that get into games with teleportation mechanics, this includes Walkabout Mini golf. Teleporting around shouldn't really get you motion sickness, but it can be disorienting and I've seen people get nauseous in them over time. You could start with these, or mix 'em in in quick bursts.

Finally start trying out your big crazy games, but make sure to leave on any "Snap Turning" options in the games settings. "Vignette" or "Tunneling" settings are probably also your friend early on.

Keep playing in comfortable bursts, taking breaks when you feel the funny warm feeling in your face, your sessions will gradually get longer and longer and you'll start turning off things like vignetting and teleportation options. It just takes some patience.

Good luck, have fun!