Missing the attraction of sex ,fucking,physical in

I've been happily married now for 19 years can't complain about much my wore is a saint and I'm a begotten sinner. The first 16 17 yeasts were awesome sex was astonishing mind blowing orgasmic..my wife loved making love having sex or fucking whatever the situation being.. Then all of a sudden one day slowly but surely my wife gets to where she doesn't enjoy sex.top the point now it's just s job or vote for her because we're married she feels obligated.it's discouraging to say the least hell my favorite pay tome in the whole world is eating pussy.love it love it now she don't even like greeting her pussy ate..what girl don't like that... I feel as though she has someone else please y'all let me know what you think..