Hello, I am pleased to help you. This is very long time, but a various viruses can be resistant and reoccur often. Apthous ulcers are common and associated with repeat episodes.Try some anti-inflammatory medication such as tylenol and advil. Benedry is an effective anti-inflammatory antihistamine. Warm salt water rinses are suggested. Antimicrobial mouth washes such as those containing chlorhexdine gluconate may accelerate healing. An anesthetic based gel such as quadragel may offer a protective coating and some relief if applied to the affected areas. Prescription medication such as a steroid available as a lozenges will be more effective and consider a rinse such as magic mouth which can be customized to your particular symptoms with anti-inflammatory, pain relief and anesthetic medications combinations. You are correct to take vtamin B and make sure you do not have any deficiencies. Make sure you have no other deficiencies such as iron and magnesium. Blood tests may be helpful to detect deficiencies. Keep well hydrated, good dental care and proper nutrition. Be sure to rule out any sharp areas from your teeth, dental appliances or habits that cause repeat episodes. Remove all irritants such as smoking, alcohol, acidic and spicy foods. Rule out any allergic reaction. Keep tract of your diet and timing of each occurrence. Look for triggers. Reactions to toothpaste ingredients such as sodium lauryl sulphite has been reported. Stress can induce episodes as well. These are steps that you can try to help with a possible diagnosis. Consider seeing an oral surgeon for a definitive diagnosis. There are other more serious conditions that should be ruled out. This is your best source for any treatmen options. Thank you for your inquiry and I hope some of my recommendations offer you relief. I am availble for additional questions.