if my car was overheating and I changed the
thermostat and the coolant gauge still goes up
and down and so does my oil gauge what else can
be wrong with my car it is a nissan pathfinder 2005
Sound like you didn't purge the air from the cooling system when refilling. The oil, check the oil level.
It may also be the result of other things, but first re-bleed the cooling system to insure no air is trapped as "Rowefast" suggests. If bleeding does not help, things to check would be the fan operation, the radiator flow, and the water pump operation. Other things may be temp sensor related. Try the simple things first!