I can’t say such a book doesn’t exist, but it might take some searching. Anyway, I recommend Cathy Yardley, who writes mainly nerdy characters. Role Playing is a good book with older gamer characters. I’m also really fond of Attachments by Rainbow Rowell.

I don’t remember if it’s specifically nerdy but Small Change by Roan Parrish rates very low on toxic masculinity.

Any subgenres you particulary like or anything else to narrow it down?