I was coming home from school today and noticed that the car was running a little odd. It seemed like it had lost most of its power. I ignored it and kept driving, well about halfway home the car started to make a ticking /whining noise, and then it stalled out. The car had obviously overheated, because there was smoke coming out from all around the valve cover, and it sounded like the oil was boiling. I let it cool down and tried to start it, but it won't do it. It cranks, but will not turn over. I was afraid that the engine may have siezed, but a friend told me that I probably blew the head gasket, and that this was causing me to lose compression, which in turn would make it impossible to start the car. First of all is this possible, and second what do I need to do to fix it. Third is what else could have happened. My temp gauge has never worked since the day I bought the car so I couldn't tell whether the engine was getting hot or not. I also need to know what to do to fix this. Any and all help would be appreciated

thanks. By the way, the engine is the I4 Zetec