The poet admits that he was in a sort of deep sleep because he did not fear the harsh reality of life. He had taken life for granted and never thought that one day death could separate him from his beloved Lucy. For him, she was like an immortal goddess who was unaffected by age and mortality.
As she is dead, she lies motionless. She cannot hear or see. She has been buried in the earth and rotates along with the Earth. One day she will get assimilated with the trees, rocks and stones that are a part of the earth.