That Others May Live — Jeff R. Spalsbury

Air Force Captain Rick Allen didn't want to save a galaxy, just some lives that others may live but sometimes you just don't have any say in such things. Sometimes, you are the chosen one. That happened the day his medical rescue helicopter flew into a mysterious energy field and crashed. He woke, transported to the Dina Galaxy in the middle of a planetary war.
Perceived as the Chosen One because of how he arrived, he becomes a reluctant leader, more frightened than brave, as he struggles to find out what happened to him and how he can return to earth. Rick learns that one man might hold the secret, the Master Kline, currently held captive by the NiLTs, a ruthless, violent enemy.
Rick teams with a white kangaroo-like alien, the sole survivor of its planet after the NiLTs poisoned it, a doctor and a 14-year-old child who communicates in music. Together, this ragtag team of four must go to war against the NiLT army of professional terrorists, rescue the Master Kline, find out how Rick can return home, and save the Dina Galaxy.
Concurrently, unknown to Rick, a comatose copy of his body was left behind after he crashed. His body becomes a pawn between doctors trying to save his life and a general and a CIA agent who want Allen dead at any cost. When Rick, in a moment of high stress, flashes back to Earth for a few minutes, he suddenly discovers that he's fighting a parallel war on two fronts, a war that he neither understands nor can completely control. But he knows that a mistake in either world will cost him his life and perhaps destroy a total galaxy. Rick realizes that if he's to make a difference, the first life he needs to save may be his own!