Kindly consult a dentist so as to get the cavities filled. The more you prolong, the more chances of you having pain and/or needing a root canal treatment. Regarding ulcers; they usually happen in case of stress or Vitamin deficiency amongst the most common causes. You can take multiple vitamin Becosule tablet once daily for a month to see if that helps. For local treatment of ulcers apply Dologel or Mucopain for temporary relief. Apply the gel on the ulcer with a clean finger tip and avoid eating or drinking anything for the next 30 mins to allow the gel to take its effect.