You guys are lucky (or maybe I'm unlucky). It wasn't that bad for me, but I got sick to my stomach a lot and had headaches and trouble sleeping, with some strong cravings. Overall way easier than trying to quit nicotine though. The cravings were not panics. I only smoked 2-3x a day for a year though.
I do know a person in my immediate family who was seriously addicted. It required a stay in rehab, and involved terrible stomach & head problems. I know that's extremely rare, but it's absolutely a thing, I watched it. That was a couple decades of very heavy daily use. I'm assuming there's a genetic component.