I agree with Dave. It is natural to want to look for "cause and effect" when dealing with this sort of problem. In order to be successful, we have to put away our tinkering tools and diagnostic manuals and simply treat our spouses as people with "free will". Of course, our first reaction to assuming that our spouses have free will in expressing or working on their desire for us may be anger or sadness. We can tolerate the idea of a spouse stricken with low desire , but we are wounded by the notion that our spouse is choosing not to have sex with us. But, then we remember... we are people with free will also (we differentiate). We can choose whether to remain married or emotionally committed to someone who is choosing not to have sex with us.
Love, like liberty, only truly belongs to people of free will who are willing to stand up for their rights. DO SOMETHING. Chant a constant refrain of "What do I want?SEX!.When do I want it? NOW!". Sit on your bed cross-legged and refuse to move until your demands are met. Go on strike; refuse to cook dinner for your spouse or refuse to eat any food prepared by your spouse. Pack your bags and say "This cock was made for f**king and these boots are made for walking." or simply state your position as clearly as possible as often as needed until your spouse chooses to meet your demands.
What do you have to lose? You know the answer. You are stuck between a rock and a hard place. There is no easy out. Be brave, express yourself, exercise your free will. Down with the tyranny of the frigid minority! Smash the Berlin wall of low desire! Vote YES for sex!
"Tell me, what is it you plan to do with your one wild and precious life?" - Mary Oliver