Tillybelle, you described my late husband to T! I eventually caught on about 11 years ago, after reading about a murderer who was diagnosed by a psychiatrist as a Narc, all the traits fitted my husband. He love-bombed me too, showered me with gifts and seemed to be my soul-mate.
Until we got married, then it was as if a switch had been flicked and he became almost a monster. Extremely controlling, extremely tight-fisted, and not a shred of empathy. Yes, he knew it all, and was impossible to argue with. However, once I realised that he was a Narc, I actually pitied him, because he was completely empty - basically a very inadequate person, who used his bullying to boost his massive ego. Apart from being ALWAYS right, he loved to pick arguments, and disagreed with almost everything I thought or said - a way of demeaning me, and destroying my self-confidence. And I learned to ignore him, and turn the tables on him whenever possible.
He died 7 years ago, from heart disease - I nursed him through several years of illness, but still felt great sadness when he finally died, but also a massive sense of freedom.