Hi, I am suffering from an acutely painful sore on the roof of my mouth at the moment, which is making it very difficult to eat or drink anything. It is also sending pain through my teeth and upper gum line on that side. I am also experiencing muscle fatigue from doing very little. I have been very tired and lacking in energy lately but the most painful symptom by far is the ulcer on the roof of my mouth. I m just wondering what could be causing it and what I should do about it?