Ole Gunnar Solskjaer says that Sunday was his worst day as Manchester United manager as the Red Devils were crushed by Tottenham.
United were on the wrong end of a 6-1 scoreline, which was the club's joint-worst loss in their Premier League history.
The match saw United's backline repeatedly undone, equalling a number of unfortunate historic marks in the process.
In addition, star forward Anthony Martial was issued a straight red card in the first half after putting his hands to the face of Erik Lamela.
The loss was one of the worst in the club's history, with Solskjaer taking responsibility while vowing to help the club turn things around.
"It's my second language so it's very difficult to put it into words," he told BBC Radio 5 Live. "It's a horrible feeling, the worst day I've had as a Manchester United manager and player.
"I've been part of big defeats before and we've bounced back so we've just got to let the boys go away on international duty, find their mojo themselves and the others that are going to stay here, we've got to help them.
"After a result like this you need to clear your mind and head and look forward.
"Sometimes you make mistakes, that's part of life and we made too many mistakes in one game of football and that shows in the result against a very good football team. They are a team full of quality and we got punished almost every time we made a mistake."
He added: "If it's a different shape, mentality, I don't know, but it will be different. We can't accept performances like this. I hold my hands up, I'm in charge and I'm responsible for this."
Former Manchester United star Patrice Evra was full of criticism following Sunday's match, saying that fans should buy a PlayStation and sign Jadon Sancho and Lionel Messi themselves if they want to see the club compete at the top level again.
He also added that several people at the club deserve "a good slap", while Gary Neville added that the players were "spiritless and spineless".
Solskjaer went on to say that a lot of Sunday's goals were self-inflicted, with the club's lacklustre defending making the game easy for Spurs while also addressing potential transfer incomings as frustration builds for supporters.
"To explain now is quite difficult. We have been beaten 6-1 at home by a very good side but we have contributed a lot to our own downfall," he said.
"The red card makes a lot of difference but Anthony Martial, well done for staying up when he was struck by the arm of Erik Lamela, you don't react but he hit his throat with two fingers, gave him a little slap and Lamela must be having an operation.
"If that was my son, I know what I would tell him. Anthony knows he should not react like that, the good thing is he did not go down but if he did maybe the other lad would be sent off.
"I know the boys wanted to and they made an effort but making mistakes, everyone makes mistake and today we made loads in the same game. That shows in the result.
"We have to address what we have. The players there are better than what we are showing and we have to come out fighting as a group. Any transfer updates, the window closes tomorrow night, then we will know."
