What are some of Winston's contradictions? What does he reassure himself with/by?
Winston Smith is a constant contradiction. Think about the journal first. Even though he knows he could totally get caught by the Thought Police, he writes down his thoughts to destroy Big Brother. He was completely attracted to O'Brien and wanted to befriend him so badly because he was sure that O'Brien was one of the good guys who would be against the government. This O'Brien character totally turns on him by the end. Winston knows better than to go to a place repeatedly, yet chooses to do it anyway for the sake of meeting up with Julia. Someone was bound to notice. Even if it wasn't a telescreen inside the place (although there does turn out to be one in there) there would have been one constantly catching him outside.
Read the character description for Smith in Enotes, it give an even fuller description.
Winston reassures himself with the idea that he is doing the right thing, even though it may in the long run cost him his life. He feels it would not be in vain because he would be working for the conspiracy against the government.