The most autobiographical songs to me are..
Always On My Mind
Pieces Of My Life
For Ol Times Sake
Thinking about you
Of course the "pills" verse was left out intentionally. It was too true to life.
As for Way Down, the "medicine within me" line has nothing to do with drugs. It is the medicine of seduction that courses through the singer's veins as the female subject takes him "way down where it feels so good" etc.