I'm not sure that you have anything wrong with you, other than dry skin. Mild eczema does seem possible. I'm not sure what your doctor meant by saying that if it were a yeast infection, the (eczema) cream would have cure it, since thee two conditions are treated differently. Having said that, I would add that your description sounds like mild eczema, not at all like yeast or any other infection. I wouldn't worry about the problem, which sounds like a mild annoyance at worst, nothing catchy, etc. Since it's continuing to bother you, perhaps the best thing would be for you to see a skin doctor, who can be more definitive about diagnosis and treatment than the doctor you saw first.
Best.
Dr. Rockoff