How Can Persistent Vaginal Yeast Infection Despite Trying Clotrimazole, Fluconazole And Itraconazole Be Treated?

I have veginal yeast infection(diagnosed as severe on every visit) since a year now. From laat 8 months i am continuously on medictaion for this. And still it remains untreated. My vaginal hygiene is good. I clean it and pat it dry. Use lactifem or vwash everyday. I have had clotrimazole, flucanozole and itroconazole 200mg throughout these months. But no help. I use candid CL or similar vaginal capsule for 7 days to treat the infection with itroconazole 200mg. The itching and infection subsides during this treatment. But 4-5 days after ending this treatment the itching returns and then the cottage cheese like infection which again gets diagnosed as severe infection. Pap smear had been taken but comes out to be just yeast infection. My sugar levels have been tested and are fine. My husband too has been treated. But after every 4 days of treatment it recurs. I also had Ecoflora capaules for 20 days. They seemed to work for 12 days but after that itching restarted and now on 17th day the cottage cheese like infection has arrived again. Please help. I am in huge stress because of this for last 10 months. Please. I have visited different doctors but they dont seem to succeed in this case.