The 27-year-old said she had a lousy year, thanks to flailing record sales for ARTPOP, mixed reviews and dwindling stardom, especially when compared to other headline-making pop performers like Miley Cyrus and Beyonce.
"I became very depressed at the end of 2013," she told the magazine. "I was exhausted fighting people off. I couldn’t even feel my own heartbeat. I was angry, cynical, and had this deep sadness like an anchor dragging everywhere I go. I just didn’t feel like fighting anymore. I didn’t feel like standing up for myself one more time -- to one more person who lied to me."
Gaga broke it off with her longtime manager Troy Carter in November. They cited creative differences, after months of rumors spats and disagreements.
"But January 1, I woke up, started crying again, and I looked in the mirror and said, 'I know you don’t want to fight. I know you think you can’t, but you’ve done this before. I know it hurts, but you won’t survive this depression,'" Gaga continued. "I really felt like I was dying -- my light completely out. I said to myself, 'Whatever is left in there, even just one light molecule, you will find it and make it multiply. You have to for you. You have to for your music. You have to for your fans and your family.'"
"Depression doesn’t take away your talents, it just makes them harder to find," she added. "But I always find it. I learned that my sadness never destroyed what was great about me. You just have to go back to that greatness, find that one little light that’s left. I’m lucky I found one little glimmer stored away."
Gaga said back in November that she becomes "severely depressed" after finishing an album, but said that touring usually "saves" her.
The latest issue of Harper's Bazaar comes out Feb. 18.
Celebrity Breakups and divorces of 2014 [PHOTOS]