Fear is a huge withdrawal symptom and so is negativity so what you're dealing with is very common. It takes a long time for our brain to repair the damage done by the drug but every cell in your body knows how to do it's job and our job is to have confidence in those wonderful little cells working away to get back to normal. You won't lose your life, but when you recover you'll have a new found gratitude for it, this is for most of us the worst experience of our lives so we come out of it humbled but happy to have survived it.