Spurs saw their aspirations of Champions League football suffer a setback at White Hart Lane as they were beaten by their North London rivals.
Chadli, who missed a golden opportunity to equalise in the second half, believes that he and his teammates deserved more from the match.
"Two days later and I'm still thinking about this game. I didn't get a lot of sleep for two nights thinking about it," the Belgian told the club's official website.
"It's a huge shame that we lost the game. We had more of the ball and more chances. We deserved more."
Tottenham are back in action on Thursday night when they face Benfica in the second leg of their Europa League last-16 tie.