Answer:
Winston truly breaks down when he is taken to room 101.
Step-by-step explanation:
Room 101 is the place, inside the Ministry of Love, where prisoners are taken to face their worst fear.
In the case of Winston, his worst fear is rats, so when taken to room 101, his head is put inside a cage where there are rats inside. Winston finally breaks down and declares that he loves Big Brother. Shortly after, the guards release him.
The problem is that Winston did not lie: he did not only say that he loved Big Brother to get released, he actually started to believe so. In the past, he had been free from Big Brother's oppression in his own mind, but after Winson's imprisonment, Big Brother's regime had managed to destroy the freedom that he had inside, and turn him into another drone of the totalitarian state.