Recurring utis!

I am CONSTANTLY getting UTIS, as in ALL the time😒 I take cranberry sachets and drink loads of water but I still get them! I get them often after a night out from dehydration and almost always from sexual activities. It always starts as cystitis and I think I'll be grand then bam, full blown UTI, and I've heard after a while your body will build up a tolerance to the antibiotics, great.
I've been referred on by the doctor but ofcourse that will take months to process. Just wondering if anyone else suffers from this and how you all deal? Especially if you have an SO, fortunately (and unfortunately) mine is out of the country for the next month or so to give me time to heal as I have had two in the past month👎🏻 Sorry for the rant!