The Latics twice squandered the lead as Swansea came through 3-2 at the DW Stadium to leave Martinez's side three points adrift of safety with two games of the season left.
"Everything was under control in the first half and I thought we were performing really well," the Spaniard told Sky Sports News.
"We conceded sloppy goals with bad decisions and that's unfortunate because you could see the effort of the players and the commitment and the desire to win the game. It made it difficult for us to be our normal selves.
"Emotionally it was such an important game for us, playing at home. When you make a mistake in that manner or you concede soft goals in that manner it becomes a bigger mountain to climb."
Wigan's final two games are at Arsenal and then back at home against Aston Villa on the final day.
"The team is ready to bounce back and make sure we take our opportunities in the final two games," Martinez said.
Before all of that is the FA Cup final, where Wigan face Manchester City at Wembley on Saturday evening.