Unfortunately, there is nothing anyone can say here that will make you feel any better. A no-start condition after an overheat is a really bad sign.
Does the engine sound normal when you crank it or does it sound 'lumpy' like the rotational speed is changing or completely free-wheeling like it is spinning fast with no resistance at all?
I presume that after it cooled, you opened the bleed screw and attempted to add water to the coolant reservoir. How much water were you able to add?
Do you hear the fuel pump click on and spin up momentarily when you turn the key to the On position?