Karen,
first, I second what hairdog said.
Have you told him this (WTF? Would it kill him to say, "Gee honey, I've been missing sex with you too. I've just been tired." or "Can't wait for your period to be over so we can have sex." ANYTHING that would lead me to believe that there was ANYTHING even slightly sexually appealing about me.)
Best to tell him when sex is not on the line, and not a possibility. Tell him how you feel when he doesn't validate you. He can't read your mind, and he probably is clueless that this is bugging you to this extent. If he knew that a simple statement would help to put your mind at rest, I'm sure he'd be forthcoming. More likely, he is seeing it as an all or nothing deal where he just isn't finding the energy, motivation or what have you to commit to a full fledged sexathon and is figuring nothing less is going to make you happy.