In a lengthy interview and photoshoot with People magazine, Bullock spoke of her joy at being a mother for the first time, and her sadness at ending her five-year marriage to motorcycle maker and reality TV star Jesse James.
"Yes, I have filed for divorce," Bullock, 45, told the celebrity magazine. "I'm sad and I am scared." She said she had adopted a son, three-and-a-half-month-old Louis Bardo Bullock, who she now planned to raise as a single mother and put her acting career on hold for awhile.
The "Blind Side" star said she and James had been working together on the adoption for four years. They welcomed the baby into their home in January but decided to keep it a secret until after Hollywood's awards season that ended with the Oscars on March 7, where Bullock was named best actress.
The People magazine spread marked the first time Bullock commented publicly on numerous reports that James had cheated on her during their marriage.
The reports surfaced just ten days after Bullock won the Oscar. She left the southern California home she shared with James and went into seclusion, taking Louis with her.
James has been publicly linked with at least four women, including a California tattoo model, and he has admitted to causing Bullock "pain and devastation." Photos of him also surfaced in the media wearing the cap of a Nazi officer.
Bullock told People she had no idea of his infidelities until she learned that another magazine was printing a story about James and the tattoo model.
"Never in a million years did I foresee something like this happening. I wish I hadn't, and it still doesn't seem real," she said.
"I did the only thing I could do, and that was pack enough clothes to live on, get all of Louis' things and get out of town." James, 41, recently spent 30 days in a rehab facility for an undisclosed addiction. He told People that "the decision to let my wife end our marriage, and continue the adoption of Louis on her own, has been the hardest.
"Sandy is the love of my life, but considering the pain and devastation I have caused her, it would be selfish to not let her go." Bullock filed for divorce in Austin, Texas on April 23 citing irreconcilable differences. They were married in 2005 and James had three children from previous relationships.
The actress described Louis - who she said was named after musician Louis Armstrong - as "the most beautiful man I know" and said she wanted to enjoy being a mother for a while.
But she showed little anger toward James, describing their current relationship as "a different one. A bittersweet one. One of new understanding. One of forgiveness. One of support for his recovery."