Hello, I Have Developed A Couple Of Skin Ulcerations Below

Hello, I have developed a couple of skin ulcerations below my left knee when using latex free cloth bandages on a cut. I have used anti-bacterial salve to no avail & tried terbinafine cream as I think that it's a fungal infection with yellow discharge from the wounds. I'm I right about fungal infections can take over if I'm a Type II diabetic with high blood sugars?