I remember when my husband got to that point. It was also followed by you need to do some changing or this is never gonna work. See me, unlike you, didn't care, didn't want to even be bothered by sex or then need to change.
It landed me almost divorced form them an I dearly love. See men want to feel desired, just as much as we do. They want to know that "you" are making love to him and not just giving him mercy sex. They know the difference just as we know the difference.
When they feel that sex is just mechanical it turns them off. They finally just say jerking off in the shower is better than having a lifeless body under them.
You two should do some serious communicating about this, If you truly want to change things he will see it. But right now he is going to be gun shy.
When I first realized it's change things or loose the only person in my life I ever actually wanted to make happy. It hit me like a ton of bricks. And while yes the majority of change was on my shoulders, he had to make some to.
One thing that worked for me, was making a conscious effort, yes you have to consciously make that effort to be sexual. If it is something you have grown used to not being it is now something you have to make yourself do then it comes naturally just like right now it comes naturally to NOT to.
As far as the foreplay, I think I am safe to say that when he starts to notice a change that is going to stay that way, not just something that is temporary he will probably be more inclined to do so...BUT, if he consistently sees you wanting to make this work and wanting to make love to him, no matter what he says he is going to react and the outcome will be good.
Something I have learned and this is my irritating line to all my friends. Sex is the biggest three letter word I have EVER seen in my life. It means so much and so many different things within a marriage. It's not putting point A into point B. It is passion, desire, love, intimacy. Cuddling on the couch is sex. You can have sex and never even have intercourse.
That's the beauty of it ...
