I asked about this a while back. I constantly sweat except under my arms, go figure. I use gold bond powder, just a light dusting about 2 times a day. I don't need to do that all the time but most days. I can be shivering with 2 sweaters on, it's 90 degrees and sweating at the same time, nights are the worst. Cotton fabrics are the best and also "modal" it's a fabric made from beech tree pulp and it wicks away sweat better than cotton, it can be hard to find but worth it. I even bought sheets made with Modal, love them.
Hang in there, SWEAT is not Sweet for us!