is my truck running hot?

You may have gotten a crack in your radiator. Unfortunately, cracks can happen at anytime. Best to have a mechanic check it out. To obtain a new one do not let the mechanic but it for you. They usually over charge. Either order from a junk yard (50/50 it could be bad), ebay (comes with guarantee or amazon (also with a guarantee).

Lets start. Your truck is twenty years old. Chances are the radiator fluid has never been changed. Same goes for the thermostat and water pump. There is also a good chance when the level was low someone stuuck the fifty foot green garden hose in the spout and turned on the spiget. None of which are good. Replace the radiator if it's leaking. Do not go the stop leak route as it may plug up your heater core. And winter is coming on strong. When the radiator is out, go ahead and pull off the fan clutch and replace it. Then take another dozen or so bolts off and change the water pump. Then undo the housing on top the engine and replace the thermostate. When you're all done, dump in 50/50 mixture of coolant. Do not purchase the 50/50 mixture as it cost sbout the same as the full strength stuff. One gallon of full strength and one gallon of water. etc. etc. When you need more down the road, only add 50/50.

Oh, and replace the upper and lower radiator hoses when the radiator is out. They're probably twenty years old also.