Eureka katiescarlett!!! You have struck gold!

(gold of coming to the realization that to the N you are an object to be used or tossed aside - at his or her whim)
I believe once the Victim of Narcissist makes this breakthrough - that nothing they do will make the N behave like the rest of humanity - the time for action has arrived. DO SOMETHING!!! Counselor, lawyer, batterd shelter, anything... ESPECIALLY if kids are involved. My stepson was raised by the N for 5 years and it completely made him an emotional wreck. Plan your escape carefully and secretly, because once the N. gets wind of being abandonded (their secret fear) they can become violent. Make notes of his behavior, recording specific instances. He may try to trick you into thinking those things didn't happen and that it must be YOUr warped thinking. DO NOT FALL FOR THAT!!!!
You deserve a life with real emotions, trustworthyness and genuine love. Your kids deserve this too. It may seem an impossible task, but I am living proof that it can be done and that the grass is wayyyy greener on the 'normal' side of life even if I am alone. Sure, he still stalks me and I am always looking around corners (because he threatened my life once), but with counseling I am standing on my own and very proud of my 'escape'.
I wish you both all the best in this terrible situation.
VoN