[RCW]

Never feel stupid. Simple problems like fuel in the oil can lead to all sorts of complexities that have to be checked and ruled out.

Only a compression test will tell you if there is permanent engine damage. But, as long as the oil was not diluted enough to run like water it is doubtful there is permanent damage.

You will want to adjust your valves after the contaminated oil has been drained and it has fresh oil.