Frequent urination persistent. For?

Hello, I was diagnosed with chronic bacterial prostatitis after a urethral swab & culture (urine culture cleat; only urethral swab showed bacterial infection); Staphylococcus infection resistant to 7 types of antibiotics unfortunately. However, four are effective according to culture results: * Ciprofloxacin * Levofloxacin * Amikacin * Vancomycin I was treated through the following plan: 10 days in January then a week's break > then most of  February &  March = 250mg Levofloxacin ↓ Early April till 18 May = 500mg Levofloxacin ↓ Symptoms practically stopped (all of them), but frequent urination returned to me MILDLY since 22/May. What should I do? How soon can I do a new urethral swab? If bacterial infection is present again, should I combine Levofloxacin 500mg OD plus Ciprofloxacin 500mg OD for better results? HOW MANY MORE MONTHS SHOULD I TAKE ANTIBIOTICS FOR? Thanks