All the Broken Pieces by Rebecca Raine

Sometimes letting your heart set the rules is a good way to lose your mind.

Jeremy Hayden knows what it’s like to be lost in someone else’s pain. After years of trying and failing to save the man he loved, Jeremy’s determined to learn how to put his own needs first. That means staying away from people who are damaged. From now on, the only person Jeremy wants to save is himself.
Harrison Winters is the kind of damaged that cracks all the way to the bone. Forged by a childhood of violence and betrayal, he lives every day on the edge of darkness. Discipline and a strict set of rules keep his mind stable and his life on track. He doesn’t need anyone to save him, no matter how broken he is.
When Harrison falls for the sunshine of Jeremy’s smile, he sees his chance for a brighter future – only to discover he is everything Jeremy has vowed to avoid. Revealing the truth about his past would bring an end to their newfound happiness. To stay silent means breaking the rules that keep his mind free from the darkness.
With his heart on the line and his sanity under threat, Harrison knows one wrong move will break him. If that happens, there may not be anything left to save.