[SPOILER FOR MOST RECENT 10 CHAPTERS]
TL;DR - MC soul split in half, half stay in IRL world, half made a fantasy world she currently lives in, her souls are connected and she must cut the connection between them for her entire soul to live in one vessel.
MC's world is just one part of her original live's soul, it split into many pieces and each created their own, with each world only exisitng around the soul fragment.
Something something cosmic entities use miserable people to create these worlds using soul fragments and then harvest them when the MC of eavc soul fragment dies.
[Not 100% sure, but close enough]
The current one was created in a final struggle where original MC's soul was about to be harvested after every world died and the soul came back as a whole after using up her creative escapism juices, and her will to survive split up her soul into two.
One is still in her original body and the other allowed for the creation of an entire world rather than just around the MC of that fragment since it was half a soul and not a small part.
MC must destroy the connection between these 2 souls by letting her original body die, and therefore having the only vessel to carry the soul in the current world.
Someone please spoil me. I felt anxious @ chap 58 cuz of the taxidermy guy so I went over the comments to calm myself… only to get confused all over again. It seems like the fl was commenting about how the og story went off tangent when ironically (based on the comments), this whole story is the same: Reincarnation cutesy family plot => Reptile Taxidermy 101 => Surprise isekai/possible trauma-induced coma/possible schizophrenia => Non fiction to fiction then back to non fiction world travel => where the hell os this story headed can someone please spoil me so I can get the closure I need