<b>How can I cope with mouth sores?</b> 

Ask your doctor if there is anything you can apply directly to the sores or to prescribe a medicine you can use to ease the pain. Eat foods cold or at room temperature. Hot and warm foods can irritate a tender mouth and throat. Eat soft, soothing foods, such as ice cream, milkshakes, baby food, soft fruits (bananas and applesauce), mashed potatoes, cooked cereals, soft-boiled or scrambled eggs, yogurt, cottage cheese, macaroni and cheese, custards, puddings, and gelatin. You also can puree cooked foods in the blender to make them smoother and easier to eat. Avoid irritating, acidic foods and juices, such as tomato and citrus (orange, grapefruit, and lemon); spicy or salty foods; and rough or coarse foods such as raw vegetables, granola, popcorn, and toast. 

Mouth sores can be so severe that nutrition and hydration are affected.  For a further discussion of mouth sores, their cause and treatment, and the magic mouthwash recipe,  &&url  on this website.