Bitter taste of defeat! So much coolant in the oil pan.

No, you should not have hurt anything......

Your detail in what has been done is good and with some effort you will find it.....

So here is how I would go about seeing if it is a Head and or Gasket problem.

Backfeed each cylinder with compressed air. I use a Compression tool hose and remove the Valve Stem. Take out your Thermostat and all plugs. 100psi will do the trick. With enough fluid for you to visually see in the Radiator you have a Head/Head Gasket problem it will show up. It is not a complicated procedure and gets this variable out of the way. If you see bubbles, movement, or anything of the sort then proceed from there.

This test has never failed me and if there is a leak it will show......

Good luck and welcome to Auto Repair 101 lol.....

JW