"Never Let Me Down" - Depeche Mode
"I feel like dying" by Lil Wayne
The Killers - When You Were Young. Relationship song in the first place, but totally applicable on opiates imo.
Most of the songs off of Siamese Dream or Melancholy and the Infinite Sadness both by the Smashing Pumpkins.
I usually put those albums on when I was on opiates and when I used them.