Coolant in oil

I would check the torque on the head bolts just to see if there was a mistake there. If they are ok and you disassemble it, then you can look for a bad gasket and try to figure out what wen wrong with it. Maybe head needs milling or is warped a bit. Low mileage gaskets don't tend to go bad all that quick, but it can happen. I would look for why though. Then use new bolts to put the head back on.