Barkley and his fellow goalkicker and Lions hopeful, fly-half Charlie Hodgson, missed six penalties between them as France compounded England's post-World Cup misery by claiming a first Twickenham victory since 1997.
'The last two games we have lost by two points and one point, and it is a bitter pill to swallow,' said Bath centre Barkley, who must be worried about how his performance was viewed by Lions boss Sir Clive Woodward.
'We have lost key players that are hard to replace, people like Martin Johnson, Lawrence Dallaglio and Neil Back, all guys when the chips are down that you can really turn to.
'We are at a learning stage now and we have to get through this,' added Barkley, who also backed skipper Jason Robinson.
'I think that Jason is leading the team fantastically well. I have been quite inspired with the way he has dealt with the side.'