2000 Jeep Cherokee 2000 Jeep Cherokee Over heating due to b

My 2000 Jeep Cherokee sport is over heating. I replaced the thermostat and flushed and filled the radiator. No luck.

Also, the starter sounds like it is dragging when I crank it, and the belt has been squealing for a while now, but it has gotten worse recently. Also, when I cranked it to see if the thermostat did the trick, it was hard to keep it idling, and it cut out a lot. I didn't allow it to run while it was hot.

My question is, could all this be because the serpentine belt needs to be replaced, or should I begin changing other parts to stop the over-heating. Water pump, fan motor etc?

Thanks in advance for any input!