The problem with your new diet is the lack of necessary nutrients in human flesh -- a dietary deficiency which will be the cause for much of your bodily decay. You can retard this decaying process with proper nutrition, which sounds simple until you remember that any food that isn't human flesh will look about as appetizing as a cat turd to you. Fortunately it should be possible to trick yourself into eating something nutritious, as your intelligence will have decreased remarkably during the zombification process. By dousing foods in ketchup, you should be able to make them palatable to your blood-seeking stomach -- we use a similar technique today with children, also presumably because of their hunger for blood.
With some pasta sauce on it, this looks basically like human brains.