If you have very bad sweaty hands there are two popular solutions:
1) Get a prescription based aluminum topical solution and apply it daily.
2) Get an Iontophoresis device and use it daily.
I would strongly advise against #1 as there are health consequences to having too much aluminum in your system. Some might say it is safe, but several doctors and chem research people I know have told me to avoid this treatment like the plague. Do as you will.
Solution #2 works, but you need to use the device for about 6 weeks for any result. It takes a long time but if you are willing to use it daily, eventually the problem will go away. I recommend googling the word Iontophoresis and then buying a device.
There are three other methods I would avoid: they can cut nerves in your hands to stop sweating but that can cause loss of feeling so that is a no-no. You can also cut a nerve under your armpit but you won't sweat in your head, shoulders, arms and hands. That is also a big no in my book. Finally botox shots work, but again things can go very wrong and this is only temporary. Good luck!