2009 was supposed to be Whitney Houston‘s big comeback year. She quit drugs, got back in the studio, released a new album and talked to Oprah about being a drug addict.

For a while it looked like Whitney was back on track, but after poor album sales for her “comeback” album I Look To You and a rejection from the Grammy’s, friends fear she’s using drugs again.

According to the National Enquirer, Whitney’s recent erratic behavior has sparked cause for concern and friends are fearing the worst.

“Everyone is worried about her,” a source said. “Whitney seems to go from being a nervous wreck to being completely out of it in a short period of time — just like she did when she was freebasing and using crack cocaine.

“She is still drinking and with Whitney, alcohol and drugs have always gone hand-in-hand. She’s worked so hard to get back on top. It would be tragic for it to go up in smoke because she can’t stay clean.

“You can’t help worrying that she’s slipped back into some of her bad habits,” added the source.

The Grammy committee usually loves comeback stories, and while other female artists like Beyonce and Taylor Swift got multiple nominations, Whitney was completely shut out.