1996 Pontiac Bonneville possible head gasket?

Engine Cooling problem
1996 Pontiac Bonneville 6 cyl Two Wheel Drive Automatic 110k+ miles

the other day I noticed that my heater wasn't working - would never warm up. And that the temp. Gauge was warmer than normal. Not over heating, but a bit higher than it usually ran. So I put 2 and 2 together, came up with 7, and decided that the thermostat was shot. I've also noticed a smell of hot anti-freeze whe ni get out of the car. A bad thermo could explain that. No big. 15 bucks, 30 minutes. So I did it. And I was refilling the raidiator and noticed it would never stay full. I knelt down and noticed a small but steady stream of water running from under the engine, on the left side with the belts. I could not identify exaclty where it originated because of all the wires, tubing and such. So, with dread washing over me I check the oil. Very little to speak of. Not dry, but very very low. So now i'm thinking head gasket, or warped/cracked head and the idea of a 2000 dollar repair right near christmas is killing me.
do you think that i'm probably looking at exactly that, or is this more likely something more simple and that i'm just borrowing trouble? I detected no oil in the water, nor water in the oil that I could see, and no steam from the tail pipe, again, that I have seen.