Please don't take this as harsh but...if divorce is not an option, then he may never see that HE has to step up as an option. Many times in cases like yours (and there are hundreds of them on this forum, just that the gender roles are reversed) it takes an ultimatum in order to cause change. The LD person has to realize that the HD person will actually LEAVE the marriage before they realize exactly how serious this is. Therefore, if divorce is not an option, then you really have no option but to just hope he changes of his own accord. Which isn't all that likely, but you already know that.
I know you were hoping to hear from other LD guys to hear what they are thinking and why...maybe to get some tips from them as to anything you could do or change to help the situation.
Unfortuantely, as you now know, no guys like that are going to come forth on this forum. I doubt they would come forth on any forum. Women with LD also do not come forth very often, and even when they do, they rarely even understand their OWN LD issues...they can't even explain why they are LD. They only know they want to avoid sex.
I was LD during my long marriage. We were essentially sexless for 15 years. It took a divorce, lots of therapy, and reading tons of books for me to really figure out why I was LD.
I found it was not my hormones (normal), it was not my upbringing (no religious stuff in the way or guilt about sex)...it was actually a mostly a result of my anger at my husband for not meeting my OTHER needs - emotional, financial, other types of support. Because he didn't meet these other needs, I went inside of myself and didn't want to meet his sexual needs. Although at the time, I didn't know I was doing this. I literally thought I just had LD and that "oh well, some women just don't want sex that often!" Over time, I finally accepted that there was indeed something wrong with me...but I still didn't know what it was. I thought I was just a messed up person. I did not realize it was actually our poor dynamic in play that zapped all my sexual hunger FOR HIM away (I still had the hunger, just not for him).
I'm only telling you this so that you can see...from within the mind of an LD person, they do not know consciously what the "problem" is. They can't just sit you down and tell you straight up "its because of x, y, z and if you just do a, b, and c, everything will be all better".
The info on the smoking is definitely at play here though...and you are correct that possibly after some more nictoine free days and weeks and months, his blood vessels will be more willing to be open.
However...his real problem is likely to be more emotional than anything else. Have you read Diane's thread? You two showed up here on the same day with the same problem....hopefully you can at least encourage each other (or cry on each other's shoulders). However, we'll all help both of you as much as we can!