I'm so glad you wrote this cautionary tale. This happened to me early last year. I ended up in the hospital for almost a week with life-threatening sepsis. Initially they thought it was meningitis and had to do a spinal tap to rule that out. Talk about absolute misery.
One note: you mentioned Phenazopyridine - I would caution it's over the counter usage without properly treating the underlying bacterial cause. It can cover up and mask symptoms and prolong the time you take to get your ass to the doctor and get proper treatment. I used it to avoid the discomfort of my UTI, but it did nothing for the actual UTI as it traveled up to my kidneys and nearly killed me.
Thanks again for writing this - such an important topic!