I completely understand your concern and I hope I am able to help you for the same.
You seem to be having extensive fungal infection
First some general precautions:
Wear cotton clothes and undergarments in order to reduce the sweating.
Do not apply any kind of oils / moisturizing lotion over the affected area .
Just give warm saline
compresses over the affected area twice a day and then apply an antifungal
Something like clotrimazole
cream helps in most cases.
Also , you will need to take oral antifungals 2 weeks.
In case of severe itching, take some antihistamine once a day .
If inspite of the above measures, the lesions continue to persist or increase , then you might have to see a dermatologist for proper assessment and management .
Hope it helps
Best wishes for a speedy recovery
Dr Geetika Paul