Oil in motor

Unfortunately that is a common failure on that engine design and in many cases ends with a replacement engine. The failure is the seals on the water pump. On this engine the water pump is inside the engine driven off of the timing chain. From the front of the water pump it is open directly into the oil pan. The issue is usually in how long it was run before the problem was discovered. If the oil was changed say 4-500 miles earlier with no signs of coolant leakage there is a possibility of saving it. However needing to add coolant because it was that low suggests it has been leaking internally for a while and that usually is a very bad thing as the coolant will cause a lack of lubrication in the bearings and other places as well as the coolant itself causing damage to the bearing due to it's chemical content. Those will cause rapid wear, and to repair that is a complete engine overhaul.
Now even if it was caught very fast it may be better to replace the engine as the replacement of the water pump requires much of the engine be removed just to replace it and with the indicated mileage I would not replace only the water pump, but all of the timing chains, tensioners, guides and check the VVT sprockets for wear. I would also replace the oil pump, the VVT solenoids and do a full engine flush to try to remove all of the coolant that was in the oil system.
For a couple videos on this that show the issue and why it's a hard choice to make -
https://www.youtube.com/watch?v=R3-NOGZL8ms
https://www.youtube.com/watch?v=xvUr_k4j9gc