Hi, the question is --- what is the diagnosis? If you are truly having infections this frequently the cultures should grow a true bladder bacteria like E Coli. Lactobacillis is a normal organism found the healthy vagina, and is not a bladder infection. As you void, the urine can pick up vaginal bacteria that grown in the culture. If these episodes are not a bacterial infection, and don't respond to antobiotics, then what are they? You need a structural study of your kidneys (CT scan or Ultrasound) and a cystoscopy (a look into your bladder and urethra) to see if there is anything causing the UTI like symptoms. A urethral diverticulum, bladder or ureteral stone, or a bladder tumor can cause your symptoms. A chronic cystitis is a deep infection of the bladder wall, often the urine culture is negative, and it can take a month or two of antibiotics to clear it.
If there is no structural/infection problem, there are two diseases that can cause your symptoms with monthly flare ups: endometriosis and interstitial cystitis. These would need to be sorted out with a urologist and gynecologist working as a team. Good Luck.
I suffer from the same problem, frequent uti's & painful doesn't even come close to the pain & discomfort I feel. I also get sharp stabbing pains under my rib cage on both sides & it lasts a couple days & than goes away. It scares me so much & keeps me up @ night!