shake (one) out of (something)

To cause one to no longer inhabit some physical or emotional state due to some sudden stimulus. The heartfelt letter from one of my fans shook me out of the rut in which I'd been stuck for several months. The attack certain shook everyone in the country out of our complacency regarding the war efforts. I find that a brisk walk around the office building helps shake me out of the sleepy slump that always follows my lunch break.