I feel so trapped.

It feels like I can't do absolutely anything in life unless I have fentanyl running through my bloodstream, easing the anxiety and stress of everyday life and of the PTSD and trauma of my childhood. I want to quit SO BAD. Even just for myself at this point. But every time I start to get the clammy skin and cold sweat or suddenly overheated or my anxiety spikes because I'm in a situation where I couldn't get anything even if I tried because no dealers are awake or available or care or maybe I have no money, I just feel like giving up on life completely. How do I train my brain to create it's own happiness again after years of heroin and fent use? How do I manage and cope with the withdrawal symptoms and somehow keep a normal stable life? I turn into a literal child with hissy fits and all when I can't get my fix to feel better for the day. If I have to go into work sick there's a 50/50 chance I might lose it and walk out. I can't keep fucking my life up like this. I haven't been able to afford to the doctors that I can go to around here and I haven't been approved for Medicaid because of my wife's income. I just need some advice on what to do during withdrawals to keep me sane and not ruin my life just to chase a high.