loosing coolant is never good. take the oil fill cap off the valve cover and look down inside. if it looks like light brown sludge, you've got a cracked head. they usually crack right under the oil fill cap. the 99-01's are the ones that crack the most. if its not that, then it might just be a head gasket.
and you said it overheated and stopped running, thats also not good
I'd take the spark plugs out and turn the motor over a few times just to make sure everything is still moving freely.