Karen, here is my concrete piece of advice to you based on my rambling, perhaps incoherent post above . Since your H is largely blaming his LD on situational reasons, perhaps you should say something like this to him the next time he turns you down. "Do you realize that you are using an excuse to avoid having sex with me that you wouldn't accept as an excuse from one of our kids for not mowing the lawn? The grass doesn't stop growing just because nobody is in the mood or feels like taking the time to mow it. My sexual needs don't disappear like magic either.". If he makes the argument that you should have more control over yourself than grass, you could say "If I am feeling healthy, happy and in love with you, I will want to have sex with you on a regular basis. Which of these factors would you prefer that I minimize in order to limit my sexual feelings?".
"Tell me, what is it you plan to do with your one wild and precious life?" - Mary Oliver
. Since your H is largely blaming his LD on situational reasons, perhaps you should say something like this to him the next time he turns you down. "Do you realize that you are using an excuse to avoid having sex with me that you wouldn't accept as an excuse from one of our kids for not mowing the lawn? The grass doesn't stop growing just because nobody is in the mood or feels like taking the time to mow it. My sexual needs don't disappear like magic either.". If he makes the argument that you should have more control over yourself than grass, you could say "If I am feeling healthy, happy and in love with you, I will want to have sex with you on a regular basis. Which of these factors would you prefer that I minimize in order to limit my sexual feelings?". 
