I have had infections of this sort 3 times - first time, I was 17 and didn't know what it was, I stopped drinking water as it hurt to pee... on day 3 I had to phone the hospital from my bed as I couldn't move - I was taken in by patient transport ambulance (I lived alone at the time)
2nd time, I was at A+E within 5 hours of first symptoms - had to pee (crying in pain) while an old man on the other side of the curtain was talking to me

3rd time I marched into my doctors surgery and begged for anti-biotics immediately... the very nice (male) doctor wrote me a prescription and through the sample I gave away, as he said it was daft to test when by the time the results came back it would be so much worse.
I don't know why I suffer this badly (possibly because I have damage from that first time) I still get sore kidneys on a regular basis.
Being from the west of Scotland the health services are often too busy dealing with toddlers ODing on their parents methadone... so before anyone asks, no I don't know if I have any long term damage...