Fungal infection on skin. Appreciated.

I have fungal infection (as diagnosed by previous doctor) in my groin area and on my buttocks and it has spread to my knee and calf muscles here and there. I have been taking tablets and applying creams on the affected area for more than three months now. My friend, who has the same problem went to an ayurvedic doctor recently and was recommended cutis cream and blood cleansing syrup, and there seems to be an improvement. Please let me know what is the best medication for intense bacterial / fungal infection on the skin. The affected areas itch a lot throughout the day, sometimes so much that I scratch for hours and wound myself. The skin has turned dark in affected areas. The affected areas are my groin area, my buttocks, small portions on both knees, similar patches on my calf muscles as well. Please help. Your advice is appreciated.