Your blower motor has nothing to do with the coolant sensor, thermostat, coolant level, etc., ........it's a separate problem altogether....
Next time it doesn't run, give it a wrap with the handle of a screwdriver....
Were you losing coolant prior to this? If yes you have a coolant leak....could be external(pump, radiator, hose, etc.) or internal(intake gasket, head gasket, etc.).....
Any kind of a leak, will create an air pocket, which will restrict coolant flow and cause the vehicle to overheat.....
It worked for awhile because you cleared the air pocket.....then once the air pocket developed again, the car overheated....