You have had children.
How?
Come on, tackle your wife again.
From the tone of your post, looks like the problem is you, not your
wife.
You expect your wife to be a hot chick.
But your wife is waiting for you.
She is wondering what happened to that horny stud.
She's thinking may be she is old and useless in sex.
Start tackling her early in the afternoon and continue until the
night, and then slowly hint at sex. Tackle her with sweet words
that makes her smile the whole afternoon.
Do not grab and rubba rubba her, like in the younger days.
Also do not just before going to sleep, shake her, grin and say
"wan or dohwan" or "can or not". Like this sure to annoy her.
Slow slow woo her again lah.
She's awaiting!