** 1. going by your history: symptoms are worsening and not getting better, it requires an Examination with Oral Surgeon /Dentist/ [roof of mouth], ENT specialist [since cough has developed] to look for any hidden/underlying pathology, [oral hygiene, blood test for infection, appropriate X-ray], and so in best Interest prior to have an appointment with them, at home, the case can be managed on the basis of stomatits . avoid food that contain acid [citrus fruits], also nuts, chocolates . stop Irritants like NSAIDs [pain killers] . take a cotton swab and soak it in any type of raw liquor, press it directly on the sore for about 2 minutes. . eat ripe pomegranate. . mix honey in cold water and gargle with this [three times a day], or you may use mouth rinse with baking soda in it. . avoid: black gram,milk,yogurt,jaggery,dry/heavy food,day time sleeping, sleeping in prone position. . You may suck Khadiradi Vati as Lozenges