I believe you might be referring to 'The Heart’s Invisible Furies' by John Boyne, which is a profound exploration of love, loss, and identity. Boyne’s storytelling is raw and emotional, making it a standout for readers who appreciate depth in their novels.
Another possibility is 'Heartburn' by Nora Ephron, a semi-autobiographical novel that blends humor with heartache. Ephron’s sharp wit and candid portrayal of relationships make this book unforgettable. If you’re looking for something more contemporary, 'The Fault in Our Stars' by John Green is a modern classic that captures the essence of heartbreak and resilience. Each of these authors brings a unique voice to the theme of heartbreak, offering readers a range of perspectives to connect with.