I'd suggest that you see a dermatologist. Patients cannot self-diagnose skin issues very well, as it requires a visual examination and there are hundreds of possible diagnoses.

It sounds like u sat up with a yeast type situation, I am overweight and when I had my first son the c~section cut was under the sag of my belly and it sit up a yeast that I had to treat with nyastatin (think I spelled it right) my son also got it on his bottom. the cream is some of the best I have found. It is mainly areas of the body that cant breathe and of course we do sweat and I can image being being disabled it is hard to tend to some needs some times depending on the disability of course. But with the sweat build up down there and the production of yeast our bodies give out it is common to sit up yeast infections~remember to keep it as dry as possible that will help! Hope u the best of luck!