“Staring at the ceiling in the dark
Same old empty feeling in your heart
'Cause love comes slow and it goes so fast”

Passenger – Let Her Go Lyrics on LyricsMode
He is up just looking at his ceiling in the dark, and in his heart he feels empty or alone. He is not complete and his heart is yerning for love. he also tells us that love happens slowly yet it ends fast. it is easy to end relationships, but to fall in love is the hard part.
He feels guilty and blames himself for being to proud to admit his love for her. He thinks of her every day and she´s constantly in his mind.