White vaginal discharge, no other symptoms. Why won’t it go away?

Patient: I got diagnosed with vaginal thrush (from being tested) quite a few months ago. They gave me pessaries and those seemed to do nothing so I took some tablets (also did nothing). I have since been travelling a lot and so has been difficult to get to a doctor. I do not have itching or soreness, the one I have is just the thick yellowy, whitish discharge. It has a strange smell to it and no matter how careful I am with soap and cotton underwear, it’s not going. I am 19. I’ve had this for so long, why won’t it go!?

Doctor: