I'm a 32 year old man, who can get it up, but can't achieve the ultimate goal of an orgasm...

A PROBLEM it is see I have the same Problem,
I do drink Liqour but I have tried going a week and a half without Sex and not Drinking for a Month but I still have a problem Getting there it stays hard: I have all the sensations of ejaculation the Throb ,the don't with it sensations but no Sperm..
I'm 39 and it started randomly when I was 36 it has caused me to be Accused of outside relations and such but I had not had relations outside of my relationship at that time.. I thought well it's the girl I'm just not excited by her anymore But that's not it..
New Girls and still no sperm.. I can materbate (which takes forever) and finely get there but not through Sex. Why?
let me think maybe its Lower back problems and Pains that's when mine started when I RE-INJURED My Back.. so guys it maybe Pain stopping your Getting there with all the mess.