Head coach Phil Neville took responsibility for England's "totally unacceptable" form after Germany's late winner at Wembley saw the Lionesses suffer a fifth defeat in seven games.
Klara Bühl's 90th-minute strike saw England beaten 2-1 in front of their largest ever home crowd of 77,768.
Asked if his side have gone backwards since reaching this summer's Women's World Cup semi-finals, Neville said: "Yes, I think so. There is no hiding from that. One win in seven is totally unacceptable."
The 42-year-old, who has been in charge since January 2018, added: "I've got to take responsibility for those results. I'm the one that picks the team. I'm the one that sets the tactics, I train them, I talk to them, I communicate with them.
"So ultimately the buck has got to start with me and finish with me, because the team always reflects the manager. At this moment the results haven't been good enough which means I've not been good enough - we need to do something about it very quickly.
"We can talk about coming down from the emotional highs to feeling the fatigue and everything of the World Cup but, when you get into November, that becomes an excuse and we're not having any excuses."
Since beating Norway in June's quarter-final, the Lionesses' only win came as they laboured to a 1-0 victory in Portugal.
Their losses to the United States and Sweden in the semi-final and third-place play-off respectively have been added to by friendly defeats against Norway, Brazil and now Germany, as well as a 3-3 draw in Belgium and October's win in Portugal.
Asked on BBC Two if he was the right person to take England forward, Neville responded: "I don't listen to those types of people saying those types of things.
"I have been in football long enough and I know I need to take responsibility, I need to make sure I improve as a manager and the players improve too. You have to take the responsibility."
Saturday's turnout at Wembley far exceeded the previous record for an England Women home match of 45,619 in their only previous appearance at the new Wembley five years ago.
But world number two side Germany were good value for their win and could have enjoyed a larger margin of victory, with replays showing Ellen White was offside before she poked home her first-half equaliser.
Neville's side will travel to the Czech Republic for their final international of 2019 in Ceske Budejovice on Tuesday.