From the standpoint of a guy I can tell you that, absent physical disease or damage, although ejaculation happens in the genitals the orgasm happens in the head. It's brain chemistry that causes the extatic rapture. And the brain also controls a man's libido. The brain is where the fantisies arise that make sex "erotic". When young, guys' erections happen spontaneously without stimulation or in a doctor's office during a hernia check or when the testicles are palpitated to check for cancer, in a locker room or other embarrassing places.
But, as one becomes older, the libido can decline, tactile stimulation may be needed to get an erection (which may not be quite as hard or last as long as when younger) and toys and porn are useful tools as a prelude to having sex with one's partner.
It is also common for younger couples to eroticize with toys, porn, bondage, other couples, etc.
But it seems to me that your husband's problem is that his threshold of erotic stimulation necessary in order to perform has been raised so high by the staged blatant eroticism of porn that he can't perform with anything less. His brain has been trained to reach arousal only by the unreal fantasies of the porn world. A loving warm body and the prospect of sex is no longer erotic enough to be of interest.
Eroticism is as addictive as a drug. One form of it lasts only so long until boredom sets in. Then one looks for something "more" which could involve the leather scene, bondage or a domineering woman with a whip or one of the many other activities some of which can be lethal.
Once the brain is fixated on the kind of erotic sex that only porn can provide those fantasies become the baseline for the libido and nothing less seems appealing. It's even worse if a guy masturbates in front of these images because there is nothing left for real life, which now doesn't seem erotic anyway.
One possible solution is to find out what turns him on and become as erotic as the porn. Maybe he likes net stockings, having sex with women wearing spike heels or leather pants with a hole to access the vagina. And vibrators can be fun, both penile and anal. Then you can become the erotic porn star that turns him on.
If I were a woman I wouldn't put up with a marriage without sex and/or intimacy. That's not what marriage is all about. It's not a business proposition of joint ownership and money counting. Give him a few warning shots across his bow and then divorce him if he doesn't get the point. Or find some guy who does care about you and spend as much time with him as your husband does with porn.
Children are always the main concern particularly if they are comfortable at home and there is no parental fighting or obvious tension. Divorce is crusing to them.
Since he refuses to se a doctor start seeing one yourself. There is always more to a story than one paragraph and you need to know as much as you can about yourself as well as him before you make the decision to leap.
Good luck.