Whenever a problem exists in a relationship, even if the problem seems to belong to only one of the partners, it is important to examine how the problem meets the needs of both partners, not just the one who carries the symptom.
In other words, instead of simply focusing our attention on your husband and 'fixing' him, we need to study both of you and find out how his sexual turn-off meets both your needs.
Let's start with what needs your husband may be meeting with this symptom. First of all, you need to know that whenever a person goes numb, emotionally or physically, the mind is cutting off from an unacceptable or unbearable feeling. In your husband 's case, he seems extremely sexually inhibited, as evidenced by his thinking foreplay is sick.
His sexual aversion didn't occur by accident. I know you question whether he is gay, and it is always possible that turning off his sexuality is a way of also extinguishing homosexual urges. His aversion to sex seems so across the board that I would also wonder if he was sexually molested as a child.
It is not uncommon for people who have been molested to become sexually numb as an unconscious attempt to cut-off from the feelings associated with the molestation.
Now, as for you. It is important for you to understand how your husband 's sexual aversion meets your own unconscious needs. Ask yourself: What do I get out his being turned off to sex?
I know you consciously hate this problem, but remember that your unconscious mind has a life of its own. And, we want to ask your unconscious mind what it gets out your husband 's sexual turn-off. Very often people marry partners who carry their unwanted feelings.
In other words, your husband seems may be voicing your own feelings of shame and inhibition when it comes to sex.
Notice how you mentioned that you are not loose. It sounds like you pride yourself on that fact and I wonder how you feel about your sexuality, about being free and responsive, about enjoying foreplay, etc. In other words, I am suggesting that your husband 's sexual aversion may also echo your own feelings about sex. And, his complete turn off to sex may be protecting you from facing your own sexual urges and the wild woman that lives inside you and every woman.
In order to heat up the sexual desert that exists between you, you both need to own how you feel about sex. Own your feelings of fear, shame, guilt, etc. When the feelings are owned and spoken about there is a good chance that they won't need to go underground.
Meaning they won't need to be expressed in actions (turning off to sex, lack of sexual feeling) any longer. In order to resolve this unpleasant symptom, the feelings need to be made conscious and discussed. By doing so you will find that the feelings will no longer need to be expressed behaviorally (turning off to sex, going numb, etc).
I would begin dialoguing with him and see how it goes. You could also suggest that you both go to couple's therapist. If he is reluctant to go with you, you can talk to a therapist on your own. Oftentimes, when one person grows a shift occurs in the couple. If you need help finding a therapist in your area let me know.
Good luck.