Pieces of Us by T.J. Hamel

Maison Beckett has always been the tough guy. The soldier. The leader. In all the years that he was a commander in an undercover operation, he never faltered. Not once. At least, not until the enemy got their hands on his little brother, Carter. Then Maison Beckett began to crack. Every day that passed was a piece of himself he lost. He sacrificed everything but his dying breath to get his brother back and bring the operation to a close, and if they’d asked he’d have given them that too.
But it’s over now. It’s time to heal. It’s time to put the pieces back together. Except, Carter hates him, he’s butting heads with his operatives, and his own trauma is refusing to be ignored. If Maison was cracking before, he’s breaking now. One wrong move and he swears he’s going to shatter.
Then he meets Nolan.
Maison read somewhere that people in Japan will pour gold into the cracks of broken pottery, highlighting their fissures instead of hiding them. They’re pieces of art – beautiful because they’re broken, not despite it.
He wonders if, with a little bit of gold, he and Nolan could become something beautiful too.