SOLVED. YA Horror/ Thriller? book about this girl in some sort of a mental facility and has split personalities that communicate through notes and at some point a fire burns down the building. Read 2017-2020. [s]

[mehe]

She has a personality for the day and a personality for the night. The night personality is more unhinged. They both are seeing a psychologist; the night one is convincing the day one to not take the prescribed pills through notes. The day one finds a friend which pisses the night one off.
The book is FULL off this diary entries and other notes in different fonts.
There were multiple scenes of the night one meeting some other ill people in a poorly lit basement of some sort.
There is an abandoned church type place in the story
The night one gets very sick at some point and near the end of the story there is a fire in the building.

[mehe]

This same author wrote another book about this girl in a mansion with woods closing in every day. Incase that helps anyone.

[Becca]

The Dead House by Dawn Kurtagich?

[mehe]

ur a literal genius

[Kris]

Glad you found your book, mehe.

The Dead House (book 1) of The Dead House series by Dawn Kurtagich - Becca's find.