HAve you had tests confirming it is a full UTI? Did they send the tests away for full analysis? Sometimes we get that burning sensation and it is not an infection - really horrid!!
You may need to up the amount of Vagifem you are using - many use it at least 3 times a week.
Cranberry is supposed to be helpful in recurring cystitis but if you have VA, with this horrid burning, anything acidic will actually make it worse. Drinking lots of water is key to avoiding infection and keeping the vaginal flora acidic. Using a vaginal gel like Hyalofemme of Multi Gyn Actigel used daily helps to keep things healthy.
Dg x