Pregnancy without sex

I've noticed that this is a very well known topic in the pregnancy world and I have found myself relating to the topic. I'm coming up on 33 weeks and with every passing week I find myself slipping into a depression. As the weeks go on we have less and less sex. Were it went from a constant routine, to getting pregnant, then it slowly disappearing, now to three weeks without it turning into four weeks and the numbers keep adding up. He tells me I'm beautiful and he my belly, but something has stopped out sex life. I love everything about being pregnant, but this is one thing that has caused me to slowly slip in a depression. Every time I suggest it or hope for it and it doesn't happen, little by little it sinks me. Today I've got no desire and at some point it will settle back into a normal mood, but I'm tired of this becoming a routine. Has anyone else felt like this? Sex between us is something I hold dear and to watch it fade out really puts a number on me. If you've gone through something like this please let me know what you did to fix the situation.