Thanks for your query.Based on the facts that you have posted it appears that you have developed Muco cutaneous candidiasis
of your genitals.
Since this is very common in diabetic person get your blood sugar levels on empty stomach and 2 hours after lunch done to rule out the diabetes
Take anti fungal medicines orally along with anti fungal topical gel for local application.
Consult your family Physician to get prescription of these drugs.