The Eagles lost 4-1 to Fulham at Selhurst Park on Monday night to fall to their seventh defeat in eight games since returning to the top flight via the Championship playoffs in May.
He told Sky Sports News: "I think you end up with the stuffing knocked out of you, but you've got to deal with it, we're not the only team to be like that.
"A win will turn it right around and realise how close that we've been. To get ourselves in front, then we needed to be even more positive, but we're putting crosses in and not getting enough bodies in the box.
"I can't fault the effort, though, that was terrific. That quality comes out in the end and we've got to believe we've got it. We've got to work at it and pick ourselves up. Now it's Arsenal."
Palace, who are currently 19th in the table, have been relegated in each of the four seasons in which they have competed in the Premier League.