Hi there popupshop! Sorry to hear that you're experiencing UTI's so frequently, that sounds super frustrating and uncomfortable to say the least! I should preface by saying that given you are getting chronic UTI symptoms that it would be worthwhile getting an STI test screening if you haven't already; in some cases the symptoms of STIs are similar to those of a UTI (and some STIs are bacterial, and therefore also are treated by antibiotics). It also could be a good idea to have your GP test that the UTI has really gone when you've finished your antibiotics, as maybe it is just getting suppressed by your initial course of antibiotics but has not fully gone, so then it just flares back again after you've finished taking them.
Following on from that, we have an article here that covers what I've said above in more detail, and also has more tips additional to those listed by your doctor that you can follow that might also assist you with preventing UTIs in future too. These includes some actions you can take and also potentially switching up the lube and/or condoms you're using for different brands in case a particular ingredient in the lube or spermicide (if you're using spermicidal condoms) might be irritating you a bit:
Out, Out Damn UTI!.
Hope this helps and if you have any further questions or curiosities about this please don't hesitate to ask!