Sick As A Dog; a person who is ill, various kinds of ailments, sick with stomach problems.
Being sick can keep you up all night. Feeling feverish, sweaty, clammy, chilly, and twisting in pain can be quite hard to fall asleep to. Waking up at intervals to take the appropriate medication can also pull you out from a deep sleep. Drastic emotional states of mind can lead to the destruction of the physical state of being. Take care of yourself, only you know your limitations well.