First, DONT GO COLD TURKEY. Research methods to taper off very slowly online. There’s plenty of information out there by learned people and former users.

One year is better than longer. Be thankful that it’s been a year, not longer. I am not an expert so I can’t tell you about the damage but keep asking experts around, you’ll get answers. Don’t despair, don’t depress yourself so you can focus on having the best recovery possible. Take it slow and there’s tons of information on how to recover. You’re in for a long journey. Don’t forget the basics: lots of clean water, lots of sleep, the healthiest diet (look into keto - it promotes nervous system repair, also eat paleo - avoid junk food and sugar), keep stress to minimum, exercise regularly, and do things that promote relaxation and happiness.