Don't think it'll be that helpful to you but I have somethin' similar as well, although it feels totally random which games cause it. I don't play many high-end games in general because every time I've tried upgrading my GPU it's caused me varying levels of strain, but with the one I use currently (RX480) like, almost every game I play tend to be fine, strain-wise. But from what I can remember from the past couple months I've had trubs with
• Sea of Stars
• Fuga: Melodies of Steel
• Small Saga
• Palworld (literally just got done playing this about an hour ago, lol.)
All of these tended to give me headache symptoms on one side of my head after about an hour in, with varying levels of severity dependin' on the game. Some I could push through, but I had to turn off Palworld cause it was making me frickin' nauseous. Figured it might be an engine thing but pretty sure all of these are all different engines. (Unreal, Unity, Construct)
Also I guess it might be worth mentioning that I played the demo for Lies of P back in the summer and it was fine for me. Now that it's been a few days how is it holdin' up for you?