Will Grigg got his first from the penalty spot after just three minutes and added two more second-half strikes as Carlisle were handed a lesson in pace and accurate passing by the Saddlers in the League One clash at Brunton Park.
"It's knocked us backwards and I'm powerless to explain it," he said.
"We need a response. Performances like that put everybody under scrutiny and we have to be ready to take the criticism.
"It has taken me by surprise. It's come out of the blue and it is difficult to explain.
"We have had a run of results, but we looked dishevelled and I can understand the crowd's frustration.
"It seems the whole world is on my shoulders, but we will come out fighting as we have done before."