hi there,you are not only suffering from Chronic UTI but also have chronic cystitis
of the blader which can explain the post void residual urine and bacterial growth
along with uti. IN simple words your bladder wall is thickened and it is not contracting properly to evacute the bladder while you pass urine leaving some of it behind whichgets infected and the cycle continuees. You will need to see a urologist
who will be able to evalute you as to the cause of your condition and if at all there is any surgical cure for it. I don't think thsi condition can be treated with medication alone. Please do get a consultation as soon as possible and start treatment, before it gets worse and affects your kidneys take care.