How much trouble am I in?

Before I even got all the way to the end I was thinking....

6T9QDA said

Change the oil and filter and see what it looks like after a few minutes?

Click to expand...

Seems to me like this would be a good first step.

One other thing that comes to mind is see if you can rent one of those testers that tell if your coolant has combustion byproducts in it.