Unfortunately if it was an untreated UTI for long enough, it could have migrated to your kidneys, thus it could be a kidney infection. Also, there are many different bacteria that can cause a UTI, and unfortunately not all meds can treat ALL of the different bacteria. That's why docs sometimes send away samples to analyze.

Not a clue what cystitis is unfortunately...

But if you're in pain, and if you're bleeding at all when you use the washroom -get to a doctor NOW - that's NOT a good thing.