Suarez, who moved to Catalonia from Anfield in 2014, opened the scoring for his current employers in a 3-0 first-leg victory at Camp Nou.
In the return leg Liverpool overcame that deficit with a 4-0 victory that shocked the Primera Division champions.
Liverpool went on to lift the trophy that Suarez and his team-mates had identified as their primary aim for the season.
More than a month has passed since that May 7 defeat but the Uruguay international can still remember the sting.
“The days after back in Barcelona were the worst moments of my life and career, along with the 2014 World Cup, I wanted to disappear from the world,” he told Fox Sports.
“I didn’t want to take my children to school, everyone could see I was in a bad way. I had days I didn’t want to do anything, they were very difficult moments.”
Suarez admitted the defeat was unexpected but confessed he and his team had failed to show the right attitude once they’d fallen behind on the night.
“I didn’t see [us losing] because we are Barcelona and we thought we’d have two or three chances to score, but we became nervous, we gave stupid passes away, we didn’t show the right attitude.
“When the first goal came we didn’t know how to react, we knew we had really messed up.
“After the game in the dressing room no-one could say anything, there was sadness, bitterness and disappointment because we knew we’d given an awful image.”
He will be fit for his country’s Copa America tilt which begins on Sunday against Ecuador.
After his return for a friendly with Panama, the 32-year-old said it felt good to be back on the pitch.
“I am happy to play again and feel physically good again,” he said after Uruguay’s 3-0 victory.