Car overheating any coolant disappearing

Hi.
If the coolant level is going down by itself, then either there is a coolant leak, or the coolant is being combusted inside cylinders because the head gasket is gone.
Check if there is a leak. If there is none, then you need to replace the head gasket.
Regards.

Hello. You state that the car is overheating.

You also state "any coolant disappearing".
I do not understand that statement.

If the car is overheating, and NO coolant is being lost, I would suggest to you to replace the thermostat.

If the car is overheating, and IS losing coolant, I would suggest that you have the water pump checked for a leak at the impeller shaft seal. If the water pump is good, I would then check for leaks in the cooling system. A radiator pressure pump will be necessary for this. Attach the pump to the radiator opening, and pump up the pressure device. After you have 15 pounds of pressure applied, start looking for coolant leaks. If you cannot see any leaks, and the pressure gauge drops rather rapidly (15 PSI to 0 PSI in about 5 minutes), you may have a bad cylinder head gasket.