I don't know if I misunderstood, but I think that Ian was drugged and SAed by that guy he kept going back to to get drugs from.
In episode 54 (I think), at the end, you can see Ian coming back after being gone for two days. He has needle marks and bruises on his arms.
And in episode 55, in the beginning, you see Ian remembering that guy saying "does it hurt? Don't worry, I'll make it feel good soon".
Ian is also wondering whether he could have stopped what happened (the SA) in some way. And he feels guilt.
So yeah, that's basically what started his addiction I would say.
I see so thats what made him start addiction...got it....thanks for explaining!!
Can some explain ian backstory like why he was addicted how it happened
..like although i read feel like didn't grasp full cause i am dumb ╥﹏╥