It appears your problem is a complicated one. In such a case I would suggest ruling out all conditions that can cause such a presentation like diabetes
, pelvic inflammatory diseases, urine infections, sexually transmitted infections, dehydration
, acidic urine, etc.
Out of the above listed conditions your doctors have ruled out most of the conditions, which is what is baffling. I would thus advise a high hydration level (drink lots of water), take special care before, during and after intercourse from the hygiene aspect. Next, wear comfortable clean cotton undergarments or avoid them completely for a while.
Go about a transvaginal ultrasound
(TVS) to further rule out a few conditions and lastly, but most importantly speak to your doctor to put you on a urine alkalizer which should surely help relieve or reduce your symptoms.
Hope I have been of some assistance.