Everton caretaker manager David Unsworth said “things have to change quickly” at the club after their poor run continued with a 4-1 defeat at Southampton.
Saints striker Charlie Austin scored two second-half headers on his first league start of the season as the Toffees capitulated after half-time.
They have now won only once in seven games under Unsworth.
“It’s killing me,” said the 44-year-old former Everton defender, who urged the board to quickly appoint a permanent manager.
“I take responsibility, but we all have to as well. We’re in a tough place and things have to change quickly.”
Unsworth said the performance at St Mary’s was “not acceptable” and the team need to “get back to basics”.
He added: “Confidence is as low as it has ever been. The club has to decide and the sooner that happens the better. The players need this resolving.
“What I see is a happy squad but I’d rather have an unhappy squad that’s winning. I want what’s best for the club and I hope the players do too.”
Dusan Tadic gave the hosts an early lead but Everton’s record signing Gylfi Sigurdsson levelled just before the break.
After Austin’s double, Steven Davis scored from the edge of the box to wrap up victory for the Saints, who had previously scored only six league goals at home this season.
This defeat came just three days after a 5-1 loss to Atalanta in the Europa League, and ex-Everton striker Gary Lineker described the club as “a shambles” as they collapsed at St Mary’s.
The Toffees seem rudderless on and off the pitch, and former defender Unsworth has been unable to add any stability since Ronald Koeman was sacked in October.
Everton have now conceded 28 goals in the Premier League this season – their worst tally after 13 games since 1958-59.