He (the person addressed in this song) has been somewhere "dark" that took his toll on him. She (the singer) is here to support and tell him everything is going to be ok. She knows what situation he is in, even if he thinks she doesn't.
"Love like you never" and the following lines are most likely about sex (or "love"). This might lead to the interpretation that the "dark place" he was in was a relationship that, according to her, did not go so well.
He (the person addressed in this song) has been somewhere "dark" that took his toll on him. She (the singer) is here to support and tell him everything is going to be ok. She knows what situation he is in, even if he thinks she doesn't.
"Love like you never" and the following lines are most likely about sex (or "love"). This might lead to the interpretation that the "dark place" he was in was a relationship that, according to her, did not go so well.