I have known patients on betahistine for years. They feel it works and are reluctant to come off it, but in truth there is no evidence that it helps after the first few days or weeks. In select patients much higher doses have been safely prescribed. But a proper evaluation of your symptoms is needed and most important is for you to understand that rehabilitation exercises are the only proven treatment longterm. Your doctor should have no confusion between BPPV and migraine related vertigo and the only treatment for BPPV are select manoeuvers

No u can not. BPPV needs rehabilitation exercises and not vertin

Beta histidine is a good drug but after prolong intake It is usually advised to tapper its dosage once you withdraw All the diagnoses which you have stated is not permanent and can be alleviated with proper counselling and exercise