My car just started running hot and not wanting.

The water pump is the least likely suspect but at the mileage you listed it's time for a new timing belt to avoid serious engine damage, and it is good practice and customary to replace the water pump at the same time. The place to start is by checking that the radiator fan is turning on when the temperature gets hot. The fan is not needed at highway speed so if that is the problem it will not overheat at high speeds.

A leaking cylinder head gasket is another possibility. If that is suspected, your mechanic can do a chemical test at the radiator to verify that.