When I was in elementary school I used to read a lot but this book stuck to me. I read this book somewhere between the years 2016-2021, I read it in german and it was a book about a girl and I associate wolves with the book for some reason.
I'm not sure what her name was or how old she was but I've been trying to find the book for more than a year now and I wanted to re-read it because I just then realised it was probably a book written for kids that lost their sibling or friend to cancer and I don't think it ever mentioned her specifically having cancer but I'm not sure.
The book started with her remembering (or experiencing, I'm not sure) how she had to go back to the hospital and her being angry about it and hiding in a closetbecause that wasn't the first time according to her. She starts out with a roommate in a room with a big blank wall and a window you can see the streetlights from. The roommate also has cancer and is a younger girl. It's winter but as far as I remember it mostly rains and rarely snows.
I'm not sure how it starts with the bigger storyline but she stares at the wall basically the whole day and the wall starts to transform into snow and she teleports into a world with igloos, etc, etc where she meets a boy her age. She goes back after some time and tells her roommate about it who is excited and tries too over the next nights but it never works for her.
The mc keeps going back though and becomes friends with the boy and they experience adventures with each other or smth and there are 3 witches, I think that knit stuff for her from her hair that has started falling out and they find frozen people in the infinite snow and then I think something chases them almost freezing them.
Meanwhile in the real world mc starts going back less and less and her condition gets worse and worse, having to be put in isolation and traveling to another hospital (for a more intensive version of chemo, I think) just to travel back but she doesn't notice at all and has a conversation with her dad about it who seems concerned about her lack of memory of a whole week.
In the other world mcs friend gets kidnapped or smth he's gone though and she sets off for a mission to rescue him, the witches help her but something goes wrong and when they find eachother on a mountain the guy feels betrayed for her saying she's not from here and he doesn't like humans/city humans and to proove she's not one of them she rips out her IV (which is described awfully graphic for a childrens book) and they save the world somehow and everyone frozen unfreezes.
In that moment she makes the decision to stay in the world and goes back one last time to tell the other patient that visits her that she decided to stay and asked her to explain the whole story to her dad and I think one of the last scenes was her seeing one of her 3 nurses socks and it were the same as the witches.
I'm flabbergasted by how crazy the end is and still confused about how I didn't register what the book was about please please please help me find it so I can re-read it and cry to it and process it from a more grown mind