Having been through my own little bit of time, really very small, only a year, in a system with absolutely no support, not even adequate support for someone like me with diet and allergy issues, I can say one thing: even if nobody helps you, you develop coping strategies. Recidivism in US prisons is not because of the prison but because of the legal system and the law enforcement. Norwegian police are obviously not as vicious and corrupt as american ones, probably because the law is not as vicious and corrupt.
Besides all this, if you go to prison, as I have, and then spent 2 years living on the streets afterwards, you would know as I do from first hand experience, that the stigma puts you outside of society. Even when they say 'oh, that's ok, shit happens' they will still deride you and disrespect you for gaving got caught in the meatgrinder.
It sounds to me like 90% of Norwegian prisoners wouldn't even be there without prohibition. To talk about the idea that you can rehabilititate people from poverty, which is the sole reason they get out and go back to dealing drugs, or fall back into addiction and engaging in theft and fraud to fund it, the problem is not the prison system but the legal system, and because of the stigma, the average joe citizen both doesn't care and doesn't know what is even going on.
I´m sorry you didn't get the support you needed. I can't say much about the american system / corruption. In Norway the goal is to work with the inmates, and motivate them to get a job, and help them find a place to live, if they dont have any. We have some places we cooperate with, where inmates can work, to get a good CV. This is a part of the plan for preventing them to end up in jail again. Hope you are doing OK now :)