Help with one yr. old

Hi all four of my followers!  :) 
Does anyone have any suggestions what I can do about the baby?  She was sleeping through the night for about two weeks and now she has been waking up, standing in her crib and screaming, crying, sobbing incessantly.  She has begun to do this at nap times as well.  She is so tired that when she is up, she yawns and cries most of the time.  And she is doing that thing where she follows me everywhere, crawling up my pants and crying for me to pick her up.
I am spent.