The climax of the novel

What is the climax of this novel? What happens? How do the events of this novel make you feel?

I think that the climax is when Winston begged O'Brien to torture Julia instead of him. Until this point, Winston had been resisting and keeping his belief; he felt love, kept diary and read forbidden books. But the time he yelled at O'Brien was a starting point of change; Winston started give up his 'right' belief and surrendered. He stopped loving Julia and commenced to love Big Brother as he was told to do. Not only the event shocked me but also made me sad; I expected the ending to be happy or at least hopeful. I hoped that Winston would carry out his plan to make the world better place. The novel suggested through Winston's surrender that the world will remain as a dystopia.