When I first saw this question, part of it asked about Big Brother's efforts to prevent personal relationships but still allow people to participate in what we usually categorize as inappropriate behavior.
In short, Big Brother seeks to destroy all human relationships that are based on emotion (specifically, those based on love or something akin to it). In the world of 1984, those who have been forced (due to fear, paranoia, torture, etc.) to severe relationship ties that existed due to emotion turn their devotion and passion to being model citizens in Big Brother's eyes. Their love for others becomes love for Big Brother. With enough people devoted to him, Big Brother's role as dictator is safe; he has nothing to fear if enough people support him. If citizens trust no one but Big Brother, they are willing to do anything to suport him, so he is guaranteed a continued future as the controller of that society.
As with everything the Party does, NEWSPEAK is a method of controlling the population. You can find lots of great information about this theme at the link below. Good luck!
The aim of creating a new language and destroying words is to ultimately limit the range of thought that the Party members have. By destroying words and simplifying the language the Party members will have a fixed number of ways in which they can express themselves and this can be closely monitored because there will eventually be so few words. When the creation or destruction of the language is complete the need for Thought Police will diminish because it will be virtually impossible to commit any serious acts against the Party because there will be no way in which to express dissension.