OCC cappuccino?

See attached photo. I put in an OCC for the first time, two months ago, at the 325,000 mark. I just checked it today and there's a milky, foamy stuff on top. Coolant, right? I emptied it out, some darker, nuttier, rich brown oil at the bottom. Kinda chunky bits, too. I'm assuming this is a clear indication of a head gasket leak? I've used two bottles of K-Seal over the past couple years due to knocking. I have to refill the coolant every few weeks, and sometimes add in a quart of oil. Also, if I have the heater on and I come to a stop, I smell the coolant quite suddenly. Once I'm moving again, it's gone. This has been going on for a long time. Heater core? I know the car probably has a terminal condition, but it's been coasting along for a couple years or so. Any suggestions to fix the coolant smell, the leak, the foam? Not going to do a head gasket repair, that's beyond my level. Thanks for any help!

 

I've noticed two different substances in the OCC. I've emptied it about 4 or 5 times now, about 20k miles later. There's a liquid that is more like Worcestershire sauce that usually settles to the bottom, and another substance that is like melted chocolate ice cream. Again, I have to add coolant and oil occasionally, indicative of a head gasket. But, nevertheless, it seems stable.