Their 2-2 draw with Odense saw the Cottagers bundled out of Europe.
"It's really hard to take," admitted a teary-eyed Hangeland to fulhamfc.com. "We didn't play a good game, but we had by far the better chances and I can't believe we drew.
"To go out like that with the last kick of the ball is very, very frustrating and hard to take.
"I've been thinking about the fact that we started on the 23rd of June and it feels like that was all for nothing at the moment, so it's very, very disappointing."