Possible pilonidal sinus disease

Patient: Hello, For the past year and a half, I thought I had a sweating problem. I would leave a sweat streak on chairs sitting for an hour in class. A Year later I felt a small hole back there (This hole is located at the top of my butt. About 4ish Centimeters above my butt hole); I looked at it in the mirror and noticed a small black hole. This hole is big enough to were I can fit my pointer finger in. I’ve put about a centimeter in but have stopped there. The hole goes straight in, and is surrounded by a black ring. I assume this is dead skin. This hole gives a foul smelling odor, and leaks some sort of puss which I initially thought was sweat. This hole has bled twice. The second time being quite bad, to were I had to use a lot of paper towel to stop the flow. My doctor told me it was possibly pilonidal sinus disease, as I did too. He gave me TEVA-CLOXACIL 500MG to take for a week, which I had zero success with. What could this be Doctor, and will I need surgery or is there an alternative to this?

Doctor: