could it be the head gasket?

[civilized_drifter]

i was driving home today and i went to give it some gas after i shifted into 4th and i had no power all of the sudden. i down shifted and gave it gas again and i tottaly lost all power and it stalled out. my friend was there with me and he checked the oil and he said that the oil is really thin as if coolant was mixed in it. i checked the spark plugs and they smelled like burnt coolent and oil and the tips were whitish brown. it started and idled until i give it a little gas and it dies. i got the car towed home and i checked the cylenders and i didnt see any coolent in there. when i wake up im gonna drain the coolent and see if there is oil mixed in there, the same with the oil.

could it be my head gasket? or is there something else that could be the problem? cause i have a spare rebuilt head and a head gasket for my spare ka and i dont wanna tear into this one if i dont have to.