AceShowbiz -

Justin Bieber was a sweet ex-boyfriend to Selena Gomez during her struggle with lupus. According to a source, the Canadian pop star helped the former Disney darling through her difficult time dealing with the illness, which she revealed recently in an interview with Billboard.

Selena opened up to the magazine earlier this month that she had undergone chemotherapy to treat the illness when she was rumored having addiction to drugs. Now a source tells HollywoodLife that the 23-year-old singer/actress was afraid before beginning treatment, particularly because she might lose her hair, but "she had Justin to support her through the whole ordeal."

Detailing the sweet actions that Justin would take to show his support for Selena, the source says, "He would always tell her she's the most beautiful girl in the world, and that it wouldn't matter if she gained weight, lost her hair, or anything." The source adds, "He would make up little songs for her...and if they were both in L.A., he'd come over and order in her favorite foods from all the most expensive restaurants in Beverly Hills."

The couple was dating on and off before they broke up for good last year. "They have obviously had a lot of ups and downs in their relationship, but he really stepped up for her," the source says of the exes, adding, "That's not to say there haven't been plenty of other times when he was a jerk, but he knew she was struggling, and he wanted to let her know he was there for her."

To Billboard, Selena also opened up about her relationship with Justin. "Of course I got my heart broken," she said of their breakup, but added that they're now in a good place. "At this point, there is no anger," she admitted. "There's closure in a very good, healthy way. We've seen each other. I'm always encouraging and I am proud of his journey. I think people are making it out to be something that is more tragic than it really was. We grew up together. We both made mistakes. That's it."