See Me by A.M. Arthur

Unmated omega Karson Jenks has already had three heats, but he’s barely twenty and too busy at university to ponder finding a mate. But all thoughts of planning his own future flee when someone he loves gets a devastating medical diagnosis. Their close-knit family rallies to support each other, and the last thing Karson expects is to stumble across his bondmate in a public lobby.
Alpha Rebel Lee spent the first eighteen years of his life as an emotional and physical hostage to brutal men, and he did his very best to protect his two adopted brothers from the worst of the violence. Two years after their rescue—and intense, in-patient psychological therapy—Rebel is a free man, eager to reunite with his beloved brothers, and to rebuild his life. What he doesn’t need is the complication of scenting his bondmate. Rebel has no job, no real education, and he lives in cheap government housing. What on earth can he offer an omega mate?
Karson is thrilled to have discovered his bondmate but also intensely curious about the Lee siblings. They aren’t blood related, have no birth certificates, and didn’t even exist on paper until two years ago. When Karson’s constable sire investigates further, the secrets he discovers rock both families to their core. With someone Karson loves dearly fighting a losing battle and Rebel terrified to step up for his bondmate, both men must learn to rely on each other to get through the most devastating week of their lives.