The Argentina international, 26, is regularly linked with moves away from the Liga giants, who are reportedly close to extending his contract.
Speaking to reporters on Thursday, Messi slammed the media for recent reports, insisting that most were incorrect.
"A lot of information about me was published in the last weeks and also throughout the year, and they were nonsense and most of them lies," he said.
"I'm feeling fine and the important thing here is that we depend on ourselves to win the title. It was a difficult year, of course, but having the chance to win the league is very important for us."
Barcelona are still alive in the title race, needing two wins – including at leaders Atletico Madrid on the final day – to defend their crown.
Messi is unsure whether that would be enough to make up for a disappointing campaign, but is pleased his team's destiny is in their own hands.
"We feel better than in previous weeks," he said.
"Now we have the chance to win the title depending on ourselves. We must make the most of this opportunity and we'll try not to fail.
"Winning the league is always important. It's very important and very hard to achieve as it's the result of a year's work. I don't know if it would make our season decent but it'd be really important."
