Jurgen Klopp said Liverpool lacked conviction in a 1-0 loss at home to Crystal Palace on Sunday, which shattered the Reds' Premier League title hopes.
Prior to Thursday's 3-0 defeat to Atalanta in the Europa League quarterfinals, Klopp's side had not lost at Anfield in 14 months across all competitions.
The German did not receive the reaction he expected, as Palace took an early lead through Eberechi Eze in a sloppy first-half performance.
Liverpool improved significantly after the break, but were undone by their usual wastefulness in front of goal in recent weeks, as Palace held on for only their second win in ten games.
"It feels rubbish, 100 per cent," said Klopp. "The first half cost us the problems we couldn't sort in the second half.
"First half we wanted to show a reaction from the last game. We saw a reaction, just not the one we wanted. You could see the team was not fully convinced. We lacked conviction."
Liverpool now trail Manchester City by two points with six games remaining in the Premier League season.
Klopp's side has three away games before returning to Anfield, with matches against Fulham, Everton, and West Ham over the next two weeks.