The historic 3-0 defeat — even if the score slightly flattered the Dutch — will pile more pressure on Loew, who opted to stay in the job after the 2014 world champion crashed out of the summer's World Cup in Russia at the group stage.
While the Dutch rediscovered their scoring touch at the Johan Cruyff Arena, the Germans have lost their way in front of goal, squandering chances that might have changed the course of what was a close match until the closing 10 minutes.
Loew's team is now goalless in its last three competitive matches.
"We are lacking confidence," said Loew. "We are not in form and we were missing a number of injured players."
Stars including Marco Reus and Ilkay Gundogan were unfit for the match in Amsterdam.
But, Loew said, "our biggest problem is that we are not taking our chances. If we had scored 1-0 it would have given the team confidence."
Germany's woes were personified by Loew's decision to play Mark Uth as a lone striker despite the 27-year-old Schalke striker not scoring a goal yet this season. Uth rarely threatened and was substituted in the second half.
"He converted a lot of chances in training," Loew said to explain his decision to play Uth. "But he had a difficult match here."
Loew brought on Leroy Sane in the second half and the Manchester City forward looked dangerous attacking the Dutch on the left, but he also missed a clear chance to equalize in the 64th minute, firing wide when he had only goalkeeper Jasper Cillessen to beat.
"The young players were a breath of fresh air, but they missed a couple of good chances maybe because of their inexperience," Loew said.
Ronald Koeman's young Dutch team lost 2-1 to France in its opening Nations League match thanks to a goal by Kylian Mbappe and a stunning winner by Olivier Giroud. The Netherlands is second in the three-team group behind France, which drew 0-0 with Germany.
"Of course I'm proud," Koeman said. "This is a fantastic result that we've been waiting for for a long time."
Koeman is rebuilding the Netherlands after it failed to qualify for the last World Cup and European Championship. The country's only major trophy is the 1988 European Championship. The Dutch have reached three World Cup finals and lost them all.
So Koeman was still keen to improve even after Saturday's victory.
"We have to look at the moments that we can do better," said Koeman, who started with two debutants and brought on a third as a substitute during the match.
Captain Virgil van Dijk scored only his second international goal on the half hour and anchored a solid Dutch defense that held out Germany, while Memphis Depay and Georginio Wijnaldum struck late to achieve the historic win.
The comprehensive defeat left Germany at the bottom of Group 1 in the new competition's top-tier League A days before it heads to Paris to take on group leader and World Cup champion France.
A corner from the right by Depay exposed German defensive frailties. Babel rose between Jonas Hector and Mats Hummels to head against the underside of the bar and the ball bounced up invitingly for unmarked Van Dijk to head in the opening goal.
Depay doubled the lead in the 87th, calmly finishing after a quick break down the right by substitute Quincy Promes. The Olympique Lyon striker then hit the crossbar in extra time before Liverpool midfielder Wijnaldum made it 3-0 with virtually the last kick of the match as Germany crumbled.
Van Dijk's opening goal came after the Netherlands had withstood strong pressure from Germany early on. Timo Werner and Jonas Hector on the right repeatedly caused problems for the Dutch defense.
After initially struggling against Werner, debutant left back Denzel Dumfries showed his attacking qualities by twice swinging in dangerous crosses from the right, first for Ryan Babel who just failed to get a touch at the far post and then in the last minute of the first half for Depay whose glancing header went just wide of Manuel Neuer's right hand post.
The performance by the young Dutch team should give fans hope for the future, Koeman said.
"Take a look in five years," he said. "I think you will see a much better team."