Compartmentalization.
Get another drive for your PC (an SSD is a better idea for gaming especially since now they're pretty cheap).
Install Windows if you want more compatible games or Linux if the games you're going to play are compatible.
Encrypt both drives and don't log in into anything important while on your gaming drive.
Try to buy all of your games on GOG or itch.io (or similar platforms where games don't have DRM).
Use different usernames between each game and/or between games that you play with strangers and your friends. Don't use usernames that you're already using, especially usernames that could link to your real identity.
Avoid games with invasive anticheats like Valorant.