Hi Dear, Welcome to HCM. Understanding your concern. As per your query you have symptoms of sore and yellowish tongue and mouth which you are talking about is infection of oral cavity known as recurrent gingivostomatitis which occurs because of reduced immunity of body or impaired immune system. It can also occur due to poor oral hygiene, stress and underlying systemic disease of body. Need not to worry. I would suggest you to apply topical antimicrobial ointment on sores. You should drink plenty of water and fluids. Apply dologel on tongue and oral cavity. Avoid hot, salty, spicy and sharp food. Eat yogurt in diet. Apply small amount of milk of magnesia . Apply ice on sores near gingival area to subside swelling and inflammation. Brush teeth very slowly and gently. Visit oral physician once and get your blood reports examined and start treatment as per that as your blood count shows presence of infection in oral cavity.. Hope your concern has been resolved. Get Well Soon. Best Wishes, Dr. Harry Maheshwari