Somebody else struggling when they need to write fics from media with fantasy/sci-fi elements or worldbuilding?

I'm not gonna lie, the sci-fi and fantasy genre are the least I read when I search manga/anime/books/games, there are some series that have some elements of it, but it's not the main thing or keep it simple so it became a bit bearable.

Now, some of the fandoms i'm from, their main genres are fantasy or sci-fi or a mix of both, and god I struggle with it.

Learning timelines, specific vocabulary, how the world works, all the internal drama of that same world and how to set it in a fic and worst if the universe is so long and vast (with different adaptations)...It's kind of mentally exhausting.

I'm just a person that like slice of life and character relationships 😭

But for some reason my brain end up with 'Like this kind of media and delete all the info except the characters relationships and imagine what they do in the every mudane day outside of the main conflict.'