Is my fish dying??????

Ok I just changed my fishes tank. I cleaned all the new decorations with water, cleaned all the pebbles, and filled the tank with room temp tap water. (the tank is 1 gallon) Then, i put 2 drops of tap water conditioner inside. I then dumped the fish and some of the water in its previous tank inside. Now he is just hovering upright on the bottom of the tank. When i tap the gl, he moves quickly but then goes back on the floor. Is he ok? His breathing doesnt seem weird.