The defeat left the Robins rooted to the bottom of the Championship table - four points adrift of safety - but O'Driscoll insists his side cannot afford to start feeling sorry for themselves.
"That is probably as much possession as we have had since I arrived at the club, yet it's our worst defeat," said O'Driscoll.
"It's a strange one because we let that disappointment affect us, which is the first time that has happened.
"Through everything that has happened, we have been really positive with the players and really positive with what we have said to them. The first bit of negativity has just come from them.
"You could see it in them and when they came in at half-time it was negative, which is disappointing.
"That can't happen given where we are in the league. We have got to handle it better.
"The players have got to be positive and view where we are as a challenge - an opportunity. Because if they don't, the next few matches are going to be torture."