3 Hours till Dead 2016

An AWOL soldier with PTSD goes into hiding along with his brother and a few friends. They retreat into a rural farm area unaware that the outside world has ceased to function. On their way back to civilization, his brother is attacked by an infected farmer. He quickly morphs into a rabid animal and lives for exactly three hours. Realizing they are in grave danger, they head back to the forest trying to outlive the legions of the infected.