This is not scientific but cranberry juice - lots of it. Make sure it's got decent actual cranberry content (Ocean Spray is good and iirc in the US you can get some pretty decent frozen concentrate which is cheaper.) If you have a mild infection it might even make it go away, but as you are seeking treatment it's probably not mild. It may make you feel a bit better though, UTIs are bloody uncomfortable so whilst the system mucks about with your health, you can try to treat yourself as best you can. All the best.

So the guy gets no care because the system is not fit for purpose?

Gawd, I know it happens more often in women but my husband had a nasty recurring UTI for a few months - they absolutely took it seriously and treated him! WTF, I hope you manage to get treated. ETA: UK

To me it feels like discovering rn in the 1980s. I hope it stays that way!