ATLANTA — The perfect storm of stench, ugliness and ineptitude enveloped the Mets on Monday in starting this crucial road trip with an embarrassing loss.

Zack Wheeler certainly was better than his final line suggested, but he wasn’t good. The lineup showed a trace of resiliency, but hardly enough. And then there was the defense, which can only strive to someday be merely inadequate. Jeurys Familia? Forget about it. By the time Drew Gagnon entered to dump kerosene on Familia’s blaze, the Mets were cooked anyway.

The sum was a 12-3 loss to the Braves at SunTrust Park that pushed the Mets four games below .500 and 8 ½ lengths off the NL East lead.

“We just stunk,” manager Mickey Callaway said. “Again, we weren’t good. We have got to recalibrate what we are doing and do the job better, plain and simple.”

In winning for the 10th time in 11 games, the division-leading Braves continued an offensive surge that has produced an average of 8.18 runs during the stretch.

The loss kicked off an 11-game road trip, which also includes series against the Cubs and Phillies, with the Mets looking much more like a team that will be selling than buying headed into the trade deadline.

“We keep on talking about that we’re going to battle back and get to .500, but we are going the opposite way,” Callaway said. “We have to get this job done, and whatever it takes. We have got to start winning games. We have got to figure out a way.”

Familia sunk further into the quicksand in the seventh by allowing three earned runs over one third of an inning to boost his ERA to 7.81. In the eighth, Gagnon allowed homers to Brian McCann and Ozzie Albies that completed the carnage.

This was Wheeler’s second straight shaky start, allowing five runs, one of which was unearned, on 10 hits and two walks over six innings. With it Wheeler’s ERA ticked closer to 5, stopping at 4.94.

“I don’t think we feel like it’s getting away,” Wheeler said, referring to the NL East race. “We know that we have to start winning some ballgames pretty soon. We’re almost to that point of the season where you have got to bear down and win games. It starts with the pitching. It starts with me. I have got to keep runs off the board.”

Robinson Cano blasted a solo homer in the sixth to pull the Mets within two runs. The homer was Cano’s first since April 21, spanning 94 at-bats and two stints on the injured list.

But with the Mets still down 5-3 in the seventh, Familia entered and allowed three runs on two hits and a walk. It was just the latest meltdown by the right-hander, who has been nothing short of a $30 million bust in his second stint with the Mets. But Callaway won’t pin all the Mets’ problems on the beleaguered reliever.

“It’s not just him,” Callaway said. “It’s almost the whole bullpen at this point.”

Wheeler had tough luck in the fifth, surrendering three runs — two of which scored on Nick Markakis’ bloop single. But Wilson Ramos’ failure to block a ball in the dirt for the second time in the game (it was scored a wild pitch) had put runners on second and third after Wheeler walked Dansby Swanson leading off the inning and surrendered a single to Freddie Freeman. Later in the inning, Albies stroked an RBI single that put the Mets in a 5-2 hole.

Wheeler’s RBI single in the fifth against Mike Soroka had tied the game following Amed Rosario’s leadoff double. Wheeler, who’s now hitting .323, walked and singled in his two plate appearances.

Pete Alonso’s RBI single in the third had pulled the Mets within 2-1. Rosario walked leading off the inning and stole second to spark the rally.

Ronald Acuna Jr. homered leading off the game for the Braves, and then the inning got ugly. Josh Donaldson’s line drive off a sliding a Jeff McNeil’s glove in left field, which was ruled a hit, put runners on first and second. Markakis followed with a grounder off Alonso’s glove for an error that gave the Braves a 2-0 lead before Wheeler escaped further damage by getting Austin Riley to hit into a double play.