Head coach Rene Meulensteen says keeping Fulham in the Premier League is the "biggest challenge" of his career.
Saturday's 3-0 home defeat by Southampton left the Cottagers bottom of the table having lost five of their past six league matches.
"It is the biggest challenge I have ever faced in football," the 49-year-old Meulensteen said.
"I think it is the biggest challenge Fulham has faced for many, many years but we can't feel sorry for ourselves."
Since Dutchman Meulensteen was appointed in November, Fulham have conceded 29 goals in 11 league games, five more than they let in under his predecessor Martin Jol in the first 13 matches of the season.
Their run of nine league games without keeping a clean sheet is the longest in the top division.
"It is very hard, but we can't rely on other teams," former Manchester United first-team coach Meulensteen added.
"It is about us, no matter what other teams do. The teams at the bottom work their socks off to get their points and teams like West Ham have a great week behind them.
"It is all about yourself - you can't look at others, you have to look at yourselves and see what we can address."
The defeat came despite a busy last week of the January transfer window at Craven Cottage, which saw the arrivals of William Kvist,Lewis Holtby,Ryan Tunnicliffe, Larnell Cole, Konstantinos Mitroglou and Johnny Heitinga.
Kvist and Holtby both made their debuts against the Saints.
"They are not coming into an easy situation," Meulensteen said. "They knew that. Credit to them that they said they still want to play for Fulham.
"At least we have some new faces in and guys who can breathe a bit of confidence into the group."