"I would wake up in the middle of the night with cold sweats, thinking I had admitted my feelings aloud," she says.
"A terrifying feeling that the person I really care about lying right next to me might have heard it, and the confusion of whether I even said anything at all."
Coupled with anxiety-induced night visions, it became a frequent concern for the singer.
"Although these hallucinations are mostly calming, and a source of curiosity. It's very rare that they are scary, but that does happen."
At its core, Sleep Talking is a song about the inability we feel to be honest to those closest to us – and to ourselves.
Written during a spell of procrastination from rehearsals, the song showcases Graham's knack for elegant minimalism in every element of her work, from playful lyrics ("God bless this mess, it turned out to be a heaven send") to sparse piano and electronic rhythms.
Still only 22, it's a remarkably mature feat of songwriting for an artist still discovering her own powers.
The track's music video keeps to that aesthetic, a swirling dream set in monochrome that tells the story of her nightly visions.
Filmed over two long days at The Pipe Factory in the Barras in Glasgow, it was an ambitious project:
"The idea was to recreate three Caravaggio paintings to act as the visions I stumble across in the dream," Graham explains.
"After lots of discussion, the details changed slightly. I really wanted to tell the story by recreating a painting from the baroque era."
Instead of creating multiple paintings, Zoe Graham and director Kieran Howe settled on creating one painting that would slowly be revealed piece by piece throughout the video – 'The Descent From The Cross' by Peter Paul Ruben.
In the video, each character in the painting represents the stages of grief, with each forming an integral and necessary process that the artist must face through her journey.
Like all great journeys, an end must arrive eventually, before the truths we hide from daylight threaten to expose us.
"The break up was very mature and conscious from both sides," the artist says of the relationship that inspired Sleep Talking.
"For me it also marked a final exhalation of truth, as if I had conquered a huge fear – and most of the things I had been worrying about were all okay."