The twenty five-yr-old's skip from the spot was a crucial instant as Chelsea sealed a ultimate place at Barca's price.
The Spanish facet were also pipped to the La Liga title by Real Madrid.
"I am still hurting from shedding the semi-closing towards Chelsea with the penalty I missed, and La Liga with the defeat to Madrid at Nou Camp," he said.
"They are both thorns in our facet. But final period is now historical past.
"It's a refreshing commence for us all. We have to put together ourselves as finest we can for what will be a challenging season.
"I hope we can get back again to successful almost everything again."
Chelsea received the Champions League semi-last three-2 above two legs with Fernando Torres' very last-moment strike generating it 2-2 at the Nou Camp, following Messi had struck the bar from the spot with the scores level on aggregate.
Barca finished 9 points guiding Genuine Madrid in the Spanish leading division, getting lost to them two-1 (only the 3rd defeat of their league marketing campaign) late in the season.
Messi scored an unprecedented 73 instances in all competitions but the Argentine now plans to priorities trophies ahead of targets, insisting he is not involved in bettering his scoring record, only enhancing his team participate in.
"I'm not searching to conquer my tally of ambitions, that is not my goal," he claimed.
"I want to try and create as a player and to give more to the crew.
"I hope I still have margin to carry on enhancing. My goal is to get more titles."
Messi has won the Fifa Ballon d'Or for the very last about three a long time jogging and hopes that if he does not claim it once again in January, it is presented to a single of his Barcelona staff-mates rather.
"There's a prolonged time to go ahead of they announce a winner," he additional.
"We really don't even know who's nominated nevertheless. What I do hope is that it stays in the Barca squad. And the more Barca nominees, the greater.
"Xavi and Iniesta are worthy of the award since of all they attained at the Euros."
