It's not only about what you you're taking tho, I remember a girl who was IVing 1200-1600 mg of 0xy every day, If you reach a point like that, I don't think it really matters what you're on.
I've grone from m0rph 60-120 mg IV a day to nothing (I got no physical symptoms, but I cried non-stop for 5 days, I hated it... lol) then opies (fent, m0rph, m3thad0ne) to a small meth@d0ne taper, that was fine. But b3nzos was BY FAR the worst, it was months of violent su1cidal ideations, like intrusive thoughts, and also hallucinations, a seizure, the worst insomnia of my life, at one point I stayed up 3 nights in a row with quetiapine, they gave me 1 mg l0razepam and I felt asleep in minutes. Opies are awful but you know it ends relatively quickly, with b3nzos you may have to wait a year before you feel normal. I will say tho, alc0hol when severe enough I've heard it's hell on earth, if you're an alc0holic, please do not go cold turkey, take long-acting benz0s like d1azepam, chl0rdiazepoxide, cl0nazepam, some people are just tired of it all and want to stop at once but with d0wners that's a terrible idea. Death is not that uncommon with alc0hol and benz0s and similar drugs like barbs.