Yeah, moving can be exhausting. But hey, you're already all unpacked! Didn't anyone tell you there's no rule saying you have to do it all in one day?
Sounds like you slept well and were eager to get up again. You'll sleep well again tonight, too.
As for hanging those pictures, relax a bit and take your time. I'm sure you want it all to be over with, but it's okay to pace yourself.
Anyway, congratulations on the new place!