Those lumps were only knots of folded skin.
I discovered that my whole body was folded from head to toes.
None of the damage was beneath the skin as I had thought; it was the skin itself that was folded.
There were no sebum mines or overgrown sebum glands; just severely entangled healthy skin.
Using my nails, I could feel cracks between the folds and open them up.
You can compare this activity to unknotting your shoelace. You have to feel the boundaries between adjoining strands of string, find a hold, and pull them apart.
Furthermore, the crossings between these folds corresponded to my aches and pains: headaches, backaches, knee aches, ... I could find their exact position and open them up, thus eliminating the pain.