is everyone still alive?
am curled up with spaniel and making a list of things I can do that will be helpful:
clean the house, at least tidy it a BIT - there is music in the cloud for exactly this kind of situation
ride, preferably with a friend (why should I go through it alone?)
do NOT cancel plans to stay with friends tonight, making pizzas and watching funny things on their TV, if you are going to be whingey and fat you might as well do it with people who care about you and will distract you
do not pull out of half marathon based on how you feel now, you know what feelings are like, they can change for the better, in fact they always do