Great Britain coach Brian Noble has admitted his players will continue to struggle against Australia until they learn to cope with high-pressure matches.
The Lions beat the Kangaroos two weeks ago to raise their hopes of ending 30 years of Australian domination.
But Britain seemed to wilt under the pressure, while Australia gave a superb display to claim the Tri-Nations title.
"We'll have to look at the emotional side of things next time," Noble told League Correspondent. Great Britain were blown away by half time as Australia ran in six tries for a 38-0 lead.
And although the second-half score was only 6-4 in Australia's favour, the match had been over as a serious contest since midway through the first 40 minutes.
"We got caught like rabbits in the headlights and saved our worst performance for the last game," said Noble.
"Hopes and expectations were very high and we did a lot of things we didn't do in the previous four games.
"Maybe emotion got the better of us.
"Sometimes you get caught in the vortex and go into freefall like we did in the first half and it's hard to stick your finger in the dyke.
"In the second half we played a whole lot better but we still didn't play the way we practised."
Noble said he had told his players in the half-time break they could not win the match, and challenged them to produce "something special" to prevent a total rout.
"The reality was I told them I didn't think we could win the game - I was trying to get their hackles up," said Noble.
"There were 44,000 disappointed people on the terraces and 17 very disappointed people in the changing room.
"The teams are not that far apart and for it to be 38-0 at half time is very disappointing.
"I thought our priority was to show that we'd been a terrific and very positive team in the tournament and we needed to regain that element of pride."
Despite the crushing loss - Great Britain's worst-ever defeat on home soil - Noble insisted he was still optimistic about the future.
"We won't lose faith though," he said.
"We get to go around next year and I'm pretty confident we'll be there or thereabouts next year."