The itching problem probably starts from inside the vagina itself. The menopause results in everything drying up and the skin becomes thin and more sensitive so the balance is out generally. Bacteria from the bowels will easily get to the whole area as well which fuels the chance of bacteria etc taking hold. Local oestrogen will, and does, help to restore the healthier environment within the vagina so should help things generally. The fillers in both the oestrogen creams and Vagifem can irritate a bit but only using the cream on the outside won't be enough.
I do think it's worth using one of the vaginal moisturisers that are available to help with dryness and these products usually help to keep the flora balance as it should be - it is trial and error with these products till you find something you like and they are often expensive but it's worth experimenting with things like Hyalofemme, Multi Gyn Actigel, Replens etc. to see if this helps. DG x