My 5/6 month old male pit bull has diarrhea?

ok last night my puppy started to have runs now today he poop and its kinda like (soft severed ice cream <--sorry) i called the vet and they are telling me they don't have appointment for another week and half and i cant wait they said but nothing else his poop smells really bad and i don't know what to do i just had a dog die on me a year ago today with Provo and I'm so scared he has all his shots and was just fixed about month ago and has front line on someone please help you can email if you have a fast answer KLux215@yahoo.com I'll be up all night watching him