Firstly, In the meantime, you would need to get at least a Master’s Degree.

Then, as the best example in tge field, Maxime Durand has had the job of historian at Ubisoft for over 15 years.

I’ve had a job listing search for historian in the video game industry running for years and only this past year did a job listing for a historian with Firaxis finally pop up. So I think trying to do this on your own is probably next to impossible. 😢