Hello, I have gone through your query and understood your concern. If you have had a negative urine culture and still experience the symptoms, despite using the suggested antibiotic, the next step would be to go for a cysto-urethroscopy. A pelvic sonogram/ MRI of the pelvis can also help to know the status of the pelvic organs and any tissue adhesions, herniations etc. The dizzy spells may be secondary to the pain, transient hypotension, anemia and so on. Regular monitoring of the blood pressure, blood work to know if any nutritional deficiencies are to be corrected and maintenance of fluid and electrolyte balance are essential. Hope this information is useful. Take care.