I would go with lamacel or tinactin cream. It will probably burn. Also, keep your feet dry and never put lotion between your toes. My son and his father both get athletes feet. You can also use the powder.
You were also asking why your symptoms are happening. If it does indeed turn out to be athlete's foot, here is some information:
"Athlete's foot is caused by fungi that thrive in warm, moist areas. Your risk for getting athlete's foot increases if you:
"Wear closed shoes, especially if they are plastic-lined Keep your feet wet for prolonged periods of time Sweat a lot Develop a minor skin or nail injury Athlete's foot is contagious, and can be passed through direct contact, or contact with items such as shoes, stockings, and shower or pool surfaces."