Campbell said: "The two results against Manchester City and Stoke have given us something to build on.
"I am confident things will continue to improve quickly. We are much more confident than we were a month ago and we have the winning mentality back.
"We have had a couple of good results but we are not going to get too carried away. Paul and Brian have made us aware of that.
"We are not out of the woods yet, even though we have taken four points from the last two games.
"We need to win three or four games out of the next seven to put daylight between us and the sides at the bottom. If we can do that we can really push on in the last five or six games.
"That is a target that is achievable because there is a real positive mentality running through the team."