Hi.. Welcome to HEALTHCARE MAGIC.. As per your complain and as you also have acid reflux the yellow coating on tongue can be due to accumulation of food debris that might be coming up with the acid as well as the sore throat and swelling is due to chemical injury caused by acid leading to inflammation.. Nothing to worry about it as it is treatable and you need to take a few medicines like Proton pump inhibitors [pantoprazole or omeprazole], antacids ike milk of magnesia before meals and take small frequent meals. You should not take large meals and spicy and acidic foods. Drink plenty of water as it helps in dilution of acid and take more of probiotics like Yoghurt. Do moderate workout, try loosing weight if you are obese and sleep with head elevated as compared to feet.. Hope this information helps.. Thanks and regards.. Dr.Honey Nandwani Arora.