After a health scare last week that landed her in the hospital, the Monte Carlo star tells her fans she was "malnourished" and "exhausted." SELENA GOMEZ REVEALS THE CAUSE OF HER MYSTERY ILLNESS! LACK OF FOOD AND LACK OF SLEEP! LAST WEEK THE MONTE CARLO STAR WAS HOSPITALIZED FOR NAUSEA AND A SEVERE HEADACHE, CAUSING HER TO CANCEL AN APPEARANCE ON FRIDAY. BUT SHE BOUNCED RIGHT BACK, AND ON MONDAY SHE HIT THE SANTA MONICA PLACE MALL TO PERFORM FOR HUNDREDS OF HER ADORING FANS. SELENA TOLD THE CROWD, "I want to thank you so much for coming. If you guys came on Friday, I’m so sorry that I couldn't be here. ... I love you guys very much." SHE ALSO TOLD REPORTERS, "I was just very malnourished, so I was low on iron and exhausted." GLAD YOU'RE ALL BETTER SELENA... NOW, YOU TAKE CARE OF YOURSELF.