Wanna see the reality of addiction, check out Darren Aronofsky 2000 film Requiem for a Dream.
This drama is about four characters who descend into addiction-fueled nightmares. It is, objectively, harrowing, terrifying, and disturbing. It's a relentless assault on the senses, an unmerciful descent into chaos, a study of four characters ziplining their way to rock bottom.