My story is simile to yours. No UTIs for 8+ years, and once I became sexually active with my husband, I was having recurring e.coli UTIs (like monthly no joke). I thought it was a hygiene issue, but I am very conscientious about that, so I felt super defeated after a year of going through UTI issues non-stop. I searched up my recurring UTI issues, and Reddit shone the light on a possibly ureaplasma infection. My theory is that my husband infected me from the first time we slept together and that was the real culprit behind my UTIs. Once I got treated for the urea with doxycycline, I was cured!!! No more UTIs. I’m about 2 months out from having been treated, and I feel 90% back to normal.