Congrats on your weight loss.
I was hoping someone had an answer to your question. I'm among the many who have the same problem, only mine was from just letting myself get fat. Now I have lots of skin that flops, too.
Cornstarch helps for sweaty areas but beware. Those areas can develop into yeast infections (there is a cream you can get a Rx for) and you don't want to use both at the same time.