I can speak from personal experience here. I have a much higher sex drive than my fella- in fact, he basically has none. It has led to much tears on my part at times, and to him feeling like a failure. He still finds me attractive, and i know he's not cheating on me, but he has no interest in sex. The saucy undies thing is one suggestion- tried that, and i just ended up feeling rejected and sad (and tearing up the undies)
Your man doesn't sound as tactile as mine though- we still hold hands and cuddle, just not much hanky panky. You must ask him about it, he doesn't sound happy. As someone said, stress and depression can be a huge factor in this, so can smoking and drinking too much. If it comes to it, you may have to decide whether you can accept an almost sexless relationship or not.
What i find difficult is that waning sex drive articles etc are always geared towards women being the ones who don't want it- we feel like we're odd! Start talking about it, and keep talking about it, or things will only get worse for you both.
I'm feeling positive about the future though- fella quitting smoking soon, and i'm coaxing him into non-sexual exercise, i'm hoping that'll help.
Chin up, i know how miserable it can be