It seems that you may be having intergluteal intertrigo
There is redness due to erythema
and fissures due to mild infection.
There may be mixed infection of fungus and bacteria.
There may be pain,itching and uneasiness.
You keep the area dry.
You may take Sitz bath in dettol water.
Apply antibacterial cream initially, then it may be combined with mild steroid and antifungal cream.
Take anti histaminics to relieve itching.
Take oral antibiotics
,antifungal and steroids intappering dose.
After clearance of the disease, you may continue to apply antifungal powder.
You might feel better.
However, you may consult dermatologist
I hope you got my answer.
Dr. Ilyas Patel MD