Pep Guardiola said he is "not good enough" to solve Manchester City's mounting problems after two late Manchester United goals consigned them to a dramatic 2-1 derby loss.
City unravelled in spectacular fashion late on as Amad Diallo struck a 90th-minute winner for the visitors just moments after Bruno Fernandes had levelled from the penalty spot.
The game-changing penalty was conceded by makeshift left-back Matheus Nunes after his poor back-pass put Ederson in trouble, but Guardiola took responsibility as he reflected on an unprecedented eighth defeat in 11 games afterwards.
"I'm the boss, I'm the manager, I have to find solutions but I don't find solutions," he said in his press conference.
"This is a big club and when you lose eight [out of 11 games] something is wrong. You can say the schedule is tough or the injuries to players, but no.
"I'm the manager and I'm not good enough, simple as that. I have to find a way to talk to them, to train them in the way we need to play, to press the way we need to press.
"I'm not good enough. I'm not doing well. That is the truth."
Guardiola signed a new two-year contract in November, saying he did not feel he could leave the club at a difficult time, but the crisis has spiralled since then and he is now facing questions over how and when he can reverse their fortunes.
"I'm here," he said. "I'm responsible. It would be easy for me to say we lost because of this action or this player or this situation but football is a team game.
"I'm completely convinced in what I'm saying, that I'm not good enough to find a way for them to feel peace in their bodies and their minds. I want it desperately. I'm here to try and I will try again and again but that is the reality."
Guardiola added: "I knew it would be a tough season but I didn't expect so hard."
Speaking to Sky Sports, Guardiola said: "This year, I would say many times this has unfortunately happened. We give away many things against Feyenoord and in games this season and at this level, it's more difficult.
"We are not, I would say, nice in the way we play. Before it was so fluid and now we struggle for different reasons - of course for a lot of defeats - but we put everything in, the game was almost closed except one chance for Bruno Fernandes.
"OK, they were a little better, more possession in the first half, but nothing special. But at the end, we give away the two goals and it's more difficult."
"It is what it is, what can I say? It is not about this action of a player, or that, it is a tough season and it will be a tough season.
"We did not play at our best today because in some positions we are not at our best, we struggled, but it is what it is.
"Now we do not play for many things, but especially for the momentum that we have.
"We obviously need results to lift our mood, but it is getting worse and worse and the reality is it is like this. I am the manager of this club and I have to find a solution. And so far, I did not find it. This is the truth."
Silva: We played like Under-15s
Manchester City midfielder Bernardo Silva pulled no punches on their performance in the closing stages, slamming their "stupid mistakes" and insisting they got what they deserved.
"At this level, if it's a game or two, you can say that they are being lucky," he told Sky Sports. "If it's 10 games, it's not about that.
"If in the 87th minute of a derby, you are winning 1-0 with a corner for your team and the ball ends up with your 'keeper and a penalty for them, my friend…
"If you make these kinds of stupid decisions with three or four minutes to go, you deserve to pay for that.
"If you look at the game, there was only one team that could win. But in the end, we lost, and it's not one game, it's a lot of games lately.
"We have to look at ourselves. It's not about luck. It's the decisions you make. Today, in the last minutes we played like Under-15s and we paid the price."
