I started getting nausea from FPS games around the time I got into my 30s. It was when Fallout 4 came out and I just had to play that game. So I did some research and found out about sea-bands. Theyre for morning sickness that pregnant women get. They worked wonders for my FPS nausea. I was able to play through many games after that without getting sick. Put them on about 10 mins before playing and wear them for the duration.

edit: clarity