Low compression and motor ticking/scratching sound

Pickup history: I purchased at 115,000 miles. Car fax report shows service from first owner up to 80,000 miles. Nothing “reported” from second owner. No issues at purchase. I was aware of some issues the 5.3 had with AFM So I immediately put a Range brand AFM disabler on to try and avoid any issues. It has burned about 2 quarts of oil in the last 4000 miles.
Pickup started making a ticking noise about 400 miles back when I was traveling but no engine light or other issues occurred. The ticking is consistent with the rpm.

I did some research and discovered a common problem the 2007.5-2008 series had with lifters and also the bolts on the VLOM not being fastened correctly. I thought this was the problem but now I’m unsure as the noise changed from a tick to a scratching sound. Attached is a video with audio so you can also hear the sound.

I am able to reach the front 2 bolts on the VLOM and they were not even finger tight. After that I ran a compression test, the results were not good:
Drivers side front to back:
50-60-90-75psi
Passenger side front to back:
65-40-125-65psi
I changed the oil last night and found shiny metal chips and shavings in the motor oil; some were stuck to the magnet, some in the bottom of the oil pan.

The fact that it is burning that much oil makes me think it’s a head gasket. The fact that there are shavings in the oil and it is making a scratching/ticking sound makes me think there may be a piston ring malfunctioning or a cam issue.
The compression test makes me think the motor has 500,000 miles on it and is completely shot. I do not know what to test next without pulling the motor and taking it apart. I have access to shop and help from a diesel mechanic but we are both perplexed.

What do you think could be the problem? What is the next step to diagnose the problem? Wanting to know how much work/cost it would be to repair before getting it tore apart.