The War Within - Vaughn C. Hardacker

Conor Quinn was a troubled kid, always one step ahead of the war. Running afoul of the local mob, he looks for a place where they would never look for him. He enlists in the USMC and is sent to Vietnam, where he wins the Medal of Honor. He returns home believing he can start over and live a normal life. However, the Marines only taught him how to kill. He's still functionally illiterate and has no means of survival than to return to the life he fled.