Since I hit my 30's My External Vagina areas is dry & chaffed alot?!

Since I hit my 30's My External Vagina areas is dry & chaffed alot?

My External Vagina areas is dry & chaffed alot, It also happens to get sore & irrated when I use mentrual pads during my periods no matter what brands I try,My skin just seems very sensitve, sometimes near butt crack it gets chaffed too & line will be red & crack, get sore for no reason
I sweat down there I live in Miami it's very hot here.
Does anyone know why or what causes this? First off I have no children, no sex recent 2 mos,Hardly douche, not yeast infections or std's been chk for that already, NO bubble baths,use ivory soap down there -seems skin is dry it gets chaffed & cracks sometimes been happening alot since I hit my 30's is this low estrogen or something? any products or home remedy that heals it up & soothes it?
I tried like vagisil products but that didnt do much. FYI thought it was my pubic hair so now I remove that with trimmers cuz shaving or those Nair type creams really make it sore down there.Shaving made it feel better for awhile but it still comes & goes

ouch!