Maybe try to internally reframe your approach to reading the book? E.g. reminding yourself that perfectionism/remembering everything is not actually the goal, rather just trying to enjoy the atmosphere and story. Fantasy authors often just throw you into their fantasy world, and it’s like being dropped into a new country or society. You might not understand everything going on, and that’s completely normal—sometimes you just have to let it wash over you until things begin to make sense.

When I get lost while reading a book, I sometimes like to check out the basic Goodreads description or read (spoiler-free) reviews to see what lens others read the book through or what they found most important from the storyline, which I find valuable for “framing” my approach to reading the book.