Kailee, 

You do need to find out what is causing this problem.  Itching, redness, and warmth in the breast could be an infection like mastitis (especially if the itching and redness seem to be coming from within the breast).  It could be a fungal type infection (especially if the itching and redness are on top of the skin.)  It could be some type of minor skin irritation (apparently that what your doctor is leaning towards).  It could also be a type of breast cancer called IBC for inflammatory breast cancer.  If your symptoms come and go, watch and see if you can figure out the trigger.  If your symptoms are constant or growing worse, either go back to your current doctor or see someone else.  Cysts can be painful, but I haven't heard of them causing redness and warmth.  Did your doctor do an ultrasound to be sure that the problem is cysts?