Driving home the temp gage shot up to H?

That description isn't a good one. I suspect you lost most of the coolant or the pump failed. The first time it started blowing cold air from the heater was due to the coolant not circulating through the heater core, If it came back a few times that was a clue that the coolant wasn't full and there was a lot of air in the system. The temp gauge reads the temperature of coolant or steam, that is why it went to hot, the last of the coolant flashed to hot steam, spiked the gauge to hot and then it went to cold because there was nothing left to measure once the steam was gone. The car died because it overheated, likely damaging the head gasket at the very least. It may have cracked the head or block as well. Step one would be to pull the dip stick and see if you have an over full crankcase, oil floats on water so coolant would settle out and raise the level above full. If it looks ok (doubtful) we can see if it still turns over. For that remove the spark plugs and look at them, if the coolant got into the cylinders the plugs that got wet will be clean and shiny from the steam cleaning. Next try turning it over with the starter, be careful though, if it has coolant in the cylinder(s) they will spurt it out like a fountain. If that happens it is pretty much a done test. You would need to pressure test the heads and block to determine where the leak is and then determine what to do. With the high mileage you have, unless the body is in very good condition you might want to replace the vehicle. If however it is in VERY good shape and paid off, you could look for a used lower mileage engine or get a remanufactured engine and install it. A used engine usually comes with a 30-90 day warranty but if it's bad you end up paying for the bad one to be replaced again, they generally swap you for another engine. The remans tend to have a longer warranty and some will cover replacement labor if there is a problem (which is far less common than with used engines)