sleepless baby

I am so tired. For the last few days Lizzie will not sleep at night. She gets up for her 2:00 feeding and then I have a hard time getting her back to sleep. If i cuddle her and rock her she will drift off but as soon as I put her into her bed she cries. Ive tried standing next to her crib and rubbing her back and her head, and ive tried letting her cry it out and its not working. This usually lasts about 2 hours at which time we both fall asleep absolutely exhausted, only to wake up an hour later for our next feeding. When will the madness end? I need some zzzzzzzz