Why can't I make my wife cum

For almost 25 years. No matter how hard I f.ck her I can't make her cum. It's really a big deal as its now affecting our relationship.

Now I l1ck her feet while she f.cks herself with a d!ldo so she can cum before I f.ck her.

She won't even let me try, that's the most painful part.

But is this really important? What do u guys think?