On my way from work tonight, first thing was the car struggled to start, second the car was blowing cold air, the engine temperature was at 90. Third, as I neared home the temperature almost shot up to maximum and then the low coolant light came on, checked and everything was fine. Fourth when I switched off the engine the fan is still blowing, just checked it's still blowing. What is going on? Will my battery die? Should I disconnect?