Narcissism is incurable .... 

Any psychiatrist will advise you to avoid these people. They have no emotions, they are excellent manipulators and love only themselves.

To the outside world they keep up an image of a pleasant friend, at home they are hell for their wife and children.

When you, as a partner, realize your mistake, it is already too late. Any therapist will advise you to leave them as soon as possible.

No therapy is possible.