The Duchess was feeling "isolated and alone".
But prior to Christmas, the cruel comments lead her to shut it down completely in order to "protect her mental health."
Chatting to The Sun they revealed: "Since she shut down her public Instagram, she'd had a fake account to follow her friends."
"There was some really vile stuff written by social media trolls and obviously she also saw the headlines about her."
"It really got to her and, in the end, she had to shut down that account just before Christmas, too, to protect her mental health. She felt very isolated and alone."
They added , "She doesn't feel safe enough to go out on her own without protection."