Perianal itching is very common. It can suppressed (creams, powders, etc.) but not eliminated. I think your three recent groin-related diagnoses have nothing to do with it, although they may have sensitized both your skin and your mind to the itching. I advise you to ask your doctor for treatment for the anal itch, treat that when needed and ignore it otherwise. One cream I've found useful is vioform-hydrocortisone 1%--ask the doctor about this or a similar cream.
Best.
Dr. Rockoff