Ralph,
in australia, once you're 14, you can go to the dr without your parents having any knowledge of anything you discuss in fact the dr can not even tell them you visited him/her.
A girl could have a total hysterectomy without her parents knowledge or consent, once she's 14 & if the dr did tell your parents then you can sue & get big bucks because it's illegal & there are cases that have been won on this basis.
You could also take the medicare card (i know not honest but) & see another dr who doesn't know you or your parents, so long as you mention the diabetes!!!!
Alternatively, go to a chemist that you don't normally visit & ask the pharmacist. Or try finding an on-line naturopathy site that might have some suggestions, or go to a library & look up solutions to sweating, cures for sweating or naturopathy books.
Good luck.