The mother of a Brooklyn teen fatally shot by gang members who mistook him for a rival said she was broken by the loss.

“This is really like I’m in a nightmare, waiting to wake up,” said Paula Aumack, whose son, Genesis Wilson, 18, was murdered on May 25.

Wilson was at a pal’s house in Canarsie when the suspects — who were hunting down his friend — opened fire through a window and shot him instead, cops said.

Aumack, 43, rushed to Brookdale University Hospital to be at her son’s side but it was too late.

“I was screaming, ‘Wake up! Wake up!’” she recalled. “‘I need you. You gotta get up.’ He was still hooked up to the machine, but I realized the machine wasn’t plugged in. He was gone! I just cried.”

That night, Wilson had been at the friend’s house playing video games. Three thugs entered the back yard, spotted him through a window and allegedly opened fire, according to cops.

Aumack said the boy who lives in the house at 6 Paerdagat 6th St. had an ongoing feud with the shooter, who was dating his ex-girlfriend.

Despite his friend’s death, the intended target isn’t cooperating with authorities, according to police.

“Do you know the agony and the pain I go through daily — knowing they are walking around freely and my child is not here?” asked Aumack, wiping tears from her eyes.

Wilson loved to cook and dance and aspired to be a veterinarian. “He loved animals. He used to bring home stray cats and dogs all the time,” Aumack told reporters inside her Crown Heights home. “He would never try to hurt anyone.”

The distraught mom compared the death of her son to the mistaken-identity murder of Bronx teen Lesandro “Junior” Guzman-Feliz, who was hacked to death with machetes and knives.