Several years ago, I ran into the exact same nausea with the Source engine as the GP, but when I increased the FOV the problem went away.
I've run into nausea with other games that have a narrow FOV. Increasing the FOV (when possible) usually fixes the problem.
As far as I understand, the late Total Biscuit was similar. He frequently advocated for FOV sliders in games. I greatly appreciate his help making FOV sliders more popular.