Let me say, ATTEMPTED relationship.
That's one thing about narcissists...I don't think they are ever really in a relationship with anyone else. They just see that other person as an extension or a resource for themselves.
I STILL have to pick up a book on narcissism now and then to remind myself how freaky and unhealthy it was. How I shouldn't love him or pine for him or just MISS him so much.
Gotta keep your feet planted in the REAL world, even when your heart and head aren't cooperating. And never go back.
Questions you will probably never have a good answer for or understand. They are a breed apart and can only be understood by other narcissists I suppose. You'll just frustrate yourself trying to find a solution to this...I know...I did everything I could and I am still feeling a bit unsettled. Try not to punish yourself any more than you have to...if I understand your situation, you have already been punished enough.
If you aren't yet MARRIED to the narcissist in question -- get out NOW.
It's worse when the narcissist is a parent or an in-law and your partner cannot or will not grow a pair.
I can imagine that is impossible. There is no room for you in a relationship with somebody who is in one with him/herself.
I dated a girl once who was extremely smart, had most of her ducks in a row...But she was just so completely full of herself. She believed she was a Disney princess. She believed everything should've been handed to her on a silver platter, with no thought or inkling of hard work or dedication, without wanting to have to earn it. I put up with her for 2 years because she was great at giving head. And then after a while, even that lost its novelty. She was a huge ***** >_>