Blown engine gasket?

My 99 jeep grand cherokee was a bout a quart low on oil yesterday and when I went to add oil, I noticed a light brown frothy looking material on the fill lid and throat. The coolant level was about 3/4 gallon low as well which I had attributed to a oin hole leak in the radiator up high on the side. Now i'm worried that I have a blown head gasket. There is no white smoke, no overheating, and the engine idles smooth. I am currently flat broke and can't afford a repair. Should I park it and wait for some extra cash? Will it hurt the engine to sit if there is some coolant in the oil? Any recommendations would be greatly appreciated.