What Causes Itching On Vagina?

DEAR DOCTOR,,I AM A 53 YEAR OLD WOMAN...THE PAST 3 TO 4 MONTHS I HAVE A VERY ITCHING IRRITATION IN MY VAGINA..SOMETIMES IT IS SO BAD THAT I USE MY CLOTH TO RUB MYSELF AND IS STARTS BLEEDING AND IS VERY UNCOMFORTABLE THEN FOR DAYS....PLEASE WHAT CAN I USE...