#’I rocked and shooked the baby’

A nanny accused of shaking a 3-month-old so hard the tot was left with bleeding in his brain was released without bail Monday, as cops revealed she confessed to the attack, authorities said.

“I rocked and shooked the baby, his head was bobbing back and forth and the baby was crying when I was doing it,” Alexis Schultz allegedly admitted to cops, according to a criminal complaint.

The live-in nanny, who was also caring for the child’s sister, told investigators she was feeling overwhelmed by her duties when she allegedly jostled the fragile infant Dec. 28 in Midwood, a high-ranking police source said.

Schultz was arraigned Monday in Brooklyn Criminal Court on one count each of reckless assault of a child, second-degree assault and third-degree assault. She was released without bail to pretrial supervision.

The baby’s parents first noticed that their son wasn’t well after he threw up all his formula last Tuesday at their home on East 9th Street near Avenue P, sources said.

The next day, they took him to the doctor, who suspected a stomach virus and sent him home. The baby continued to deteriorate and his parents took him to the hospital on New Year’s Day, where an examination revealed that he was suffering from an old bleed and a new bleed in his brain — indicating he had been shaken before.

He had also suffered retinal hemorrhages in both eyes.