I know how you feel. Ive tried not to feel bad about it since everybody tells me to rest as much as I can before he's born.
I have the same problem and i also have a 3 year old so i cant sleep unless he is ready for a nap but i feel alittle bad he wakes me up and we play a hour or a hour and a half later i am ready to go take a nap.
I am as well. Everything just exhausts me. I need a nap after everything from a shower to grocery shopping.