Hi
Sounds to me like you could have Vaginal Atrophy which often causes nasty UTI's. A few years back I kept getting them and doc kept dishing out anti bios, never once mentioned VA. Did my own research, got myself some treatment in the form of local estrogen and haven't had a UTI since.
There are a lot of threads on here about VA symptoms and causes. Type it into the search box and you?ll get loads of info.
Hope this helps
W xx