Car COMPLETELY dead?!?!?!! HELP

Honestly based on what you are describing DO NOT attach any battery to the car for your own safety. It could be the battery but usually if a problem occurs there, only one or two cells would go at once causing a drop of around 1.5-2v at a time. It could be possible that the charging system fried it if there is a problem. But I’d find it hard to believe that it completed shorted all the cells in the battery. Considering the car was running ok a few hours ago.

However, based on the fact it started boiling just when trying to charge it seems to indicate a possible short. So DO NOT connect a battery until you test for that first. Last thing I want to hear is a story about an exploding battery and a missing face.

Attach an ohmmeter = without any battery in the car from the positive and negative terminal. It should be next to infinite with the key off, if it isn’t or it’s near 0 then you have a short somewhere. Look at that first. Most likely though your battery is now toast.