The hosts were leading thanks to a 20th-minute penalty from Cauley Woodrow, but the game changed in the second half with the introduction of Lewis Grabban on the hour as Forest switched to 4-2-3-1 with devastating effect and Barnsley went to pieces.
Grabban saw played a part in Philip Zinckernagel's leveller on 61 minutes before Brennan Johnson - outstanding on the restart - put the visitors ahead after racing clear and Grabban grabbed a late third after Barnsley were again opened up during a desperate final half hour when they imploded from a defensive and tactical aspect.
The final whistle was the prelude to a welter of boos from disgruntled home supporters, who justifiably let their feelings known.
On the criticism from fans, Schopp, whose side host Millwall on Saturday, said: "The fans are coming to the games and want to see passion and three points from the home side and I can totally understand this.
"We have to give them all the (right) stuff and it does not matter what is going on.
"This is about us and we have to find better solutions. And we will find solutions. They have to step up and take more responsibility.
"Right now, this is a tough one for all of us, but my experience says that in this situation things can happen in a positive way and we have to handle the situation as a group and not as individuals.
"Last season, with a couple of guys, nobody knew about them and they are now well known and teams are finding different solutions and now it is up to them with their quality to find their next solutions. We have to support them as much as possible.
"It was a tough one as we had to change formation before the game as Josh Benson could not play and we had to adapt. It is not an easy situation. A lot of things are coming in and we have to react.
"We know it is a tough situation, but I know the guys want to find a way out.
"The first two goals were really big punches for the guys and the reaction was not good after that."