Doctors and medicine

I'm a long-term excessive coffee drinker. Due to a recent health blip I decided to give it up altogether, finding total abstinence easier than moderation. My god...for 3 nights I had such severe kidney pain I couldn't sleep. I could barely cope at all. Found out it wasn't kidney pain but pain from the adrenal glands, which sit atop the kidneys.
It was the most harrowing withdrawal I've been through. Much harder (for me) than giving up cigarettes.

I had those terrible headaches for a few days, but the lower-back pain trumped them. I read online that the hit from coffee is from the adrenal glands. I had no idea they were involved. I was a 20-cup-a-day drinker. Sometimes more. Two spoons of coffee and two of sugar in each cup.
I guess that's why withdrawal was so dramatic...but it's compensated for by how well I'm feeling at the moment. Not just mentally (I'm less anxious) but physically (I feel much lighter).