Kristen Stewart
Kristen Stewart Reuters

Kristen Stewart is reportedly struggling to come in terms with her split from Twilight co-star and boyfriend Robert Pattinson.

The couple had broken up last year after it was confirmed that Stewart cheated on Pattinson with British director Rupert Sanders.

"Kristen's been trying to have a good time, but it's difficult while Rob's on her mind," a source told Star magazine, "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."

Pattinson and Stewart became famous after starring opposite each other in the hugely successful and popular Twilight series of fantasy vampire-themed films, based on novels of the same name by Stephenie Meyer

Last month, Stewart got a tattoo on her right wrist while on a road trip with friends in Nashville, Tennessee. She was spotted at the Pride and Glory Tattoo Parlor, which posted pictures of Stewart on their Facebook page. In one of the photos, she is seen holding up her arm and showing off a small tattoo on her wrist.

"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 insider said.

Meanwhile, Pattinson threw a Great Gatsby themed birthday party for his friend and Arbitrage director Nick Jarecki on 22 June, at his Los Feliz, Hollywood mansion, but Stewart was nowhere to be seen.

"Rob wants to remain friends with Kristen, but felt having her at the party would be inappropriate," the source added.

Kristen Stewart at Paris Fashion Week

Stewart was recently spotted at the Paris Fashion Week. At Zuhair Murad show, the 23-year-old actress wore a silk bustier and lace trousers from the Lebanese designer's couture Fall/Winter 2012/13 collection. She previously attended the Chanel show, wearing a white tweed blazer and black shorts.