It is phenomenal how fast a little toot of smack will take away the agony of withdrawal and most other kinds of pain. What it cannot take away it makes meaningless. You may still have a broken arm, but somehow it doesn't matter so much. The same is true for angst and anxiety. It cancels pain so hidden that you were unaware of its existence until it disappeared.
Edward Bunker (2012). “Mr Blue: Memoirs of a Renegade”, p.261, Oldcastle Books