Oh that’s so disheartening! Many years ago I had a chronic UTI as well and was on low Bactrim for over a year. But prior to that I’d gone through years of issues but no one could find the culprit.
Finally, with a new urologist, the doctor zoned in on the answer. I had a scope of my urethra and bladder to rule out any issues inside. They did a 5 day culture of my urine and a swab of my urethra.
The culture provided the answer with a bacterial growth that wouldn’t show up in a rapid test or even the 3 day culture. It was explained to me that there are microscopic folds of tissue in our urethra that can hold bacteria.
Even though I’d been on Bactrim and a plethera of other meds before, it was suggested to try this low dose for a year because it was the antibiotic that killed the samples in the Petri dish.
It work for me. Have you had a 5 day culture run?

Not sure if this would help you at all but I have a friend who has found relief from her UTIs with this product from Uquora. I’ve not tried it personally. But it may be something worth trying or running past your doctor to see if you can use the product. 🙂
https://uqora.com/