The temperature gauge doesn't work. The coolant depletes quickly from the reservoir. I don't know if the head gasket is blown.
The temperature gauge issues may be the result of a faulty coolant temperature sensor or a low coolant level. If there is no coolant in the system, the sensor cannot read temperature accurately. It would be best to consult the aid of a professional. The technician can perform a cooling system pressure test to locate any coolant leaks and make necessary repairs.