Out of these, I shortlisted:
Umberto Boccioni, States of Minds II: Those Who Go (painting, 1911)
Set in a train station, this painting explores the psychological dimension of modern life's transitory nature. It was part of Futurism, the social and artistic movement that sought to de-stabilize anything from the past and emphasize speed, vitality, violence and motion
David Lynch, Mulholland Drive (film, 2001)
A néo-noir mystery, this film not only showcases pronounced mental instability in its characters, but also follows an extremely unstable and non-linear narrative structure.
Frou Frou, Let Go (song, 2002)
This electronic indie song addresses emotional instability and encourages the listener to give in to the chaos and appreciate the beauty in the breakdown.
To begin with, I re-cropped Boccioni's painting in an upside down triangle on its tip, and the rest of the book had stills from Mullholand Drive interspersed with lyrics from the song, following a narrative similar to the one in the movie on a very high level.
My first iteration was a book without a discernible cover, butterfly bound together loosely. It had an extension on the base, allowing it to be completely balanced when untouched, but causing it to fall over as soon as someone interacted with it: