Broken Warrior by K.C. Wells

War is hell. It cost Gary Cross his military career, his love, and left him with a roadmap of scars that serve as a constant reminder of everything he lost. Out of that tortured past came something extraordinary—CrossBow Protection, one of the premiere bodyguard services in the US.
Michael Kennedy has been Gary Cross’s personal assistant for nearly a year. He’s come to understand why none of his predecessors lasted more than a few months. Gary Cross is snarly, prickly, and snappy, and those are his good points. But Michael is not like the others—as Gary is about to find out.
A job for the government proves hard to refuse, but it isn’t long before Gary and Michael realize that by protecting one man, they’re risking everything Gary has built—and bringing death to their front door.
But this time Gary won’t let go. Even though it could lose him what he holds most dear.