It's wrong to laugh at a suicide attempt.
Ken is talking with his friend Luke and tells him that he recently tried to kill himself with pills but it didn't work.
Luke wants to respond to the news of the failed suicide attempt.
Luke tells Ken that he is really concerned about him and hopes Ken will let him find help for him.
Luke laughs heartily and tells Ken that he's a loser who can't even get suicide right and then keeps laughing.
Ken is relieved that Luke will try to get some help for him and happy that his friend is concerned for his well being.
Ken is devastated because not only is Luke making light of his misery he's also insulting him and depressing him further.