There Has Been Excessive Chafing And A Mix Of Reddened

There has been excessive chafing and a mix of reddened skin, plaques and overall dry skin as well as dirt marks inbetween stretch marks along my inner thigh as well as the perernium. Truth be told I recall this starting when I was young (about 11) in a very small localized area but despite cortizone and antifungal cream, it's still persisted and I haven't been able to stop itching. The discomfort will go for days or hours at a time but will come back. I'm 22 now, 5' 8'' stocky build at 230. It's spread to cover most of the perenium and the skin color has almost vanished and is lighter (im brown) and nothing that I've tried has worked. My parents both have diabetes, my father only prediabetes and he's kept it under control. My mother has Type 2. I personally do not have it and despite my recent weight gain, I've strived to remain healthy and feel great overall. It's just this skin issue that's bugging me.

My father also recently has been treated for psoriasis, so I thought this might be it, but nothing from what I saw on him (he had it on his face but had it treated/maintained) matched what is on me. Thanks for taking the time to answer.