I have had chronic thursh, the doctors put me on intraconzole 100mg daily for the next two months in a bit to kill it all off for good.
Its a broader antifungal and its well known for thrush, i only found out about it from lots of research on the internet googling chronic thrush infections. I had to tell my doctor to try me with this cos clotimotrizole and fluconzole wasnt even touching the infection.
Mines cleared up nicely, maybe it could work for you too x