The Twilight star is not coping well after splitting with long-term boyfriend, Robert Pattinson, who has since moved on with actress Riley Keough.
The former Twilight stars' romance was hit hard when it emerged Kristen had been cheating on the British actor with director Rupert Sanders.
Since then their relationship has been rocky and earlier this year the pair decided to call it quits for good. Kristen is said to be taking the split badly.
"Kristen's been trying to have a good time, but it's difficult while Rob's on her mind," an insider told British magazine Star. "She can't be bothered to eat and the weight is dropping off her. She's not in the best place right now and saying she can't cope without Rob."
The 23-year-old seems to be keen to move on and even got her first tattoo while in Nashville recently. In snaps posted by the parlour on Facebook, Kristen is seen holding up her wrist with a tiny, unidentifiable design.
"She put on a brave face and got her first tattoo while in Nashville to try to get into the spirit of the trip, but nothing seemed to cheer her up," the source sighed. Meanwhile, Robert seems to be coping well and has even been linked to brunette pop beauty Katy Perry.
Last month the hunk threw a party for a close pal's birthday, but didn't appear to invite his ex-girlfriend. "Rob wants to remain friends with Kristen, but felt having her at the party would be inappropriate," the source explained.