Me, too!
Started around the same time as my hot flashes (which do not make me sweat, they just make me want to rip off all my clothes and run naked through the trees).
I carry a bandana pretty much all the time in my purse. I can use it to mop up the ludicrous rivers of sweat from walking up a flight of stairs, and also use it to put my hair up if my sweat-flood ruins my coiffure.
The excess sweat thing is probably my least favorite part of perimenopause. No-one can see my hot flashes or the other personal details I'm experiencing, but the sweat is undeniable. Icky.
"If Americans want to live the American Dream, they should go to Denmark." - Richard Wilkinson