My experience is this, i got this frequently when in nl and it stopped when i came to ch, I then recently received all my stuff from nl, towels, underpants and i could not believe it after 3 years i got it again, i was so upset, i tried the d-manose and for a full blown infection it did not work but as a preventative i think it should work very well.
what i think happened is the bacteria may still be lurking in my towels and underwear, try maybe boil washing them? i did this and so far so good.
someone else mentioned yogurt and i think this is key, the antibiotics kill the good flora which significantly help your bowel health and general health, i was also given norofloxocin, it has a side affect on the joints for a small number of people of which i have discovered i am one so that powerful (and potentially wonderful) antibiotic i can only really use if my life is in danger. in nl the amoxil i can't remember the rest of it worked for me every time with no side affects. for the yogurt i recommend the 1.5% at aldi it has some bacteria in it that make me feel good i can't explain it better than that, i use it to make my own. you can make a smoothy in the morning with it. after antibiotics, just gorge yourself on it for a while, then lower doses.
i do feel for you, its both psychologically and physically draining (My nan almost died from it) and according to the internet the second most frequent reason doctors prescribe antibiotics, you are not alone in this.
so maybe in summary add to preventative measures
- boil wash the bejeasus out of everything, maybe put it in a dryer on high too from now on
- gorge yourself on yogurt (Make your own its easy)
this link also has some other advice about onions, turmeric, virgin coconut oil (did not work for me with a full blown infection but as a preventative measure, i cook with coconut oil and onions are a regular part of my diet) I also use apple cider vinegar, so far so good.
good luck