I feel you are living my life with the exception of the fact that I only have a 12 mo-old :-) I too am in my mid 30's with a very LD husband. I read your post and to be quite frank felt a bit jealouse...you'r H will initiate?...and every 4-6 weeks to boot?! I WISH! LOL. For us we can go indefinitely if I don't just get fed up and force the issue and I am always the one who must initiate...or it won't happen. We actually went a year at one point...and he thought nothing was wrong...can you imagine?! LOL.
Anyway...I picked up a copy of SSM and read it...that was the beginning of my taking the steps in mending our relationship in a constructive instead of destructive (albeit unintentionally so) manner. My H is now attending counseling and things are ever so slowly moving in the right direction :-)
One thing I'd like to encourage you to do when you do talk to your H about your situation is to keep things in "I" terms...such as "I feel...". Now if your H is anything like mine he may take that "I feel..." statement and say your are trying to put words in his mouth...I've finally managed to get past that but I've had to do some constant reinforcement that I'm not "saying" he said something to me...I'm "saying" that when he does (or doesn't) do (or say) something that it makes me feel a certain way. For example...I told him one time that when I initiate sex and he doesn't respond to me at all (he would completely act as though I hadn't done a thing) that I feel ignored, undesireable, rejected ect. His knee jerk reaction to my statement was..."I never said that!" So I calmly said...no, I didn't say you "said" that, I said it makes me "feel" that way when you give me no response whatsoever to even acknowledge I'm in the room. That's just an example though. One thing I did have to drive home with him however is that I wasn't on a fault-finding mission...I wanted to work on our marriage...I knew there was behavior I had to have that was eliciting certain responses out of him (and I was correct) that was adding to the vicious cycle of emotional disconnectedness that we were experiencing...I wanted to find out how I could change my behavior to help us.
Also...a couple of questions that I didn't notice if you had addressed or not. Has your H had a medical examination to check his testosterone and other levels as well...I have a feeling that's probably not his problem...but you never know? My H did have a thorough checkup and everything came back normal, so on to the next step.... Do you think he'd be willing to attend counseling on his own or with you? For my H and I this has been very helpful...if nothing else the 3rd party has helped us learn to communicate with each other in a more effective manner...and we're really learning to hear what each other says. Our counselor was able to say basically the same things I had been trying to say to my H for quite some time...but she was successful...she had the tools to fly in under his radar and I realized no matter how long I tried talking to him or what approach I may have taken...there was a good chance he may never have heard me...but he was willing to listen to a professional 3rd party. Hope this post didn't skip around too much for you...it's still very early here and I haven't had my coffee yet