I have been having intense itchiness in my private area and breasts area for a few months, what can it be?

Detergent allergy: When itching occurs in moist areas or areas that make tight contact with clothing, think of detergent allergy first. Change to all-free detergent and avoid fabric softeners for 2 weeks, if your symptoms continue, see your doctor.

See a physician: You mention breast infection and vaginal itching. You don't say what infection. For instance, yeast (candida infection) can cause both conditions, particularly if you are overweight. However, this is a guess. Without additional information, i can't be more specific. See a gynecologist first and if necessary a dermatologist. Don't wait.