I'm glad you posted this, as I was planning on making a similar thread. I've had HH my whole life, but really started to notice it about 12. It was more concentrated in my hands and feet back then, but it grew in to full body HH. At the age of 14 or so I started seeing doctors to figure out what was wrong with me. I had full blood work, exams, ekg, etc. They couldn't find anything wrong with me. I recall one doc saying " you're healthy as a horse, but that sweating is impressive " I eventually went to see a psychiatrist because I was extremely depressed and anxious. I also had a horrific case of acne, which of course contributed to the mental anguish. Anyway, he tried a few meds on me and eventually came to the combo of Paxil and Klonopin. That combo helped me ALOT. Not only did it help with my depression and anxiety, but it seemed to bring the sweating way, way down. I'd say from 16-24 I was almost HH free. I still sweated alot, but more like the upper region of " normal "
I've been reading alot about Benzos lately and found some interesting info. It seems that there is alot of evidence pointing to benzos lowering the amount of norepinephrine and acetylcholine the body produces. Those are the main chemicals involved in a " overactive sympathetic nervous system " the thing doctors say us HH sufferers have. I believe THIS is what was helping me so during those years. Unfortunately, over the years I believe two things happened: 1. I developed a tolerance to the drug, so that the dose began to lose effectiveness. 2. I began bodybuilding and went from 160lbs to 220lbs, which also increased the need for a larger dose. I actually haven't been on Klonopin for two years or so, as I didn't like the idea of being of two meds long term. However, since my HH has gotten so terrible these last few years, I now believe that I will have to take a benzo for many, many years. I was using 0.5mgs 3 times a day for years. But again, I feel that the dose became too low. I am going to the Dr. next week and am going to ask for 1mg 3 times a day.
People all too often dismiss psych meds, but we have to keep in mind that they DO work on chemicals in the body. We tend to look at them in more of an abstract way I think. But really, it's not much different than taking insulin for diabetes. If you have chemicals in your brain or body going haywire, they need to be treated.
Anyway, that's my story.

One note of caution: benzos can be pretty addictive. Though I went cold turkey on Klonopin after 13 years and it honestly wasn't TOO bad. The Paxil is another story. I honestly don't believe it does anything for me, but trying to go off of it is like pure mental and physical torture.