"Downtime" by Gustavo Bondoni - Paperback

Tinini, a former soldier with cutting-edge cybernetic implants, struggles to survive the overwhelming pain and anxiety of her hardware. Despite the war’s end, her systems remain in a constant state of high alert, making everyday life unbearable.
 
Desperate for relief, she turns to a dangerous dealer for a stronger dose of illegal substances, and after injecting the drug, her implants seize control, driving her to kill before she regains her senses and seeks a way to escape her deteriorating sanity.
 
Her quest leads her to a risky experimental procedure designed to temporarily disconnect her from her implants. Fearing the procedure’s high failure rate, she escapes the station, only to find herself increasingly out of control, committing murder and abduction along the way. 
 
Military bureaucracy, and her own unraveling mind, forces her into space, and to a station where she acquires black-market drugs, hoping to manage her worsening condition. In a desperate quest for a cure, Tinini experiments on her captives, facing grim outcomes. 
 
She receives an offer of help from an old contact but rejects It, feeling isolated and hopeless, and opts instead for a final risky solution, a mysterious grey cube that could end her torment—and her life
 
Bracing for the unknown, she grips the cube, ready to confront her final, grim fate.