@Gamer87 I've had/have lots of skin issues and I doubt everything has been diagnosed. Looking at images of this I wouldn't be surprised if I have had this along with some of the things that were diagnosed. I've been to numerous dermatologists, but it was just too time consuming to go to one any time I had anything that looked slightly different (and with appointment timing could easily be gone anyway).
I found I had to stop using antiperspirant & deodorant completely. It was just too irritating, not matter what it was. If I go to something where it's going to be hot and I want to be reasonably fresh I use baby powder, but even that's not the best for my skin. Most of the time I just try to stay clean - extra showers, or wiping down and sometimes I do use antiseptic agents like benzalkonium chloride.
I did get laser hair removal and the initial plan was to do that just to reducing shaving and the irritation that comes with it. I was really expecting that to flare up my skin issues short term, but was surprised to see my skin actually improve both short and long term with doing that. When I do shave over an area that is irritated/was recently irritated I use a new razor and don't use it for anything else. It can be expensive, but I thought it was worth it.
I do try to be careful with clothing. Most of my clothes are 100% cotton, cotton with a bit of spandex or bamboo. I try to avoid things rubbing, but It's hard as so much can be an issue. When I'm home I will often change to things that might not look so great but don't cause problems. For sleepwear, I bought a bunch of mens t-shirts. The cut has much looser arms and as a bonus they are cheaper than most women's clothing.