CLEVELAND — Three months after her rescue from a quiet house where she had been held captive for a decade along with two other women, Michelle Knight, 31, confronted her abductor, Ariel Castro, 53, in a courtroom here on Thursday, offering an emotional last act to a traumatizing story.

“I cried every night, I was so alone,” said Ms. Knight, who was 21 when Mr. Castro enticed her into his home in 2002 with the offer of a puppy for her young son. “Days never got shorter. Days turned into nights, nights turned into days. The years turned into eternity.”

Ms. Knight, who was held longer than the other women and was the only one who offered a statement at Mr. Castro’s sentencing, told him: “You took 11 years of my life away. I spent 11 years in hell. Now your hell is just beginning.”

A tiny woman with auburn hair, Ms. Knight let tears run freely while speaking of how her bonds with the other kidnapped women, Amanda Berry and Gina DeJesus, gave her a sliver of hope. “We said we would someday make it out alive, and we did,” Ms. Knight said.