Welcome to HCM,
You are young diabetic and having repeated fungal infections, you should visit a dermatologist
and take proper local and systemic anti fungal therapy sometime we have to give anti fungal treatment for long time.
Please also maintain good hygiene and you should also make sure your partner is also treated simultaneously so as to avoid source of infection.
Please keep good control of diabetes
and once infection is cured keep the area dry and use of barrier method of contraception
may be useful for you.