Car will not start after overheating problem

I was stuck in traffic for over an hour when the car started overheating. The temperature gauge stood at normal, but I could smell the heated vapors. I pulled into a petrol station and the car switched off by itself and wouldn't start again. I bumped into a mechanic who said the gasket was fine the battery just needs a kick and we filled the car with water and antifreeze. I then drove off, but the same thing happened again. I filled the water with water and got a jump start. As I needed to get back home, I drove for about 20 minutes, after filling the car with water and pouring some on the radiator itself and starting from cold. I then realized, after that 20 minutes, driving at 100k/h, that the car was heating up again. I stopped, went through the same routine, but then the car wouldn't start anymore. Even with the battery- to -battery connection jump starting. I got towed home. Took the battery for charging overnight. But the car still would not start. One mechanic I contacted said to fill the car to the top with water, see if the water bubbles when the key is turned. The water did bubble, and he said the top is blown.
Is this true? Is there a solution? The water is clear, the oil is still brown-clear.
Another mechanic I called said, if the water pump is not working, the water can bubble.

Please help me make an informed decision.