It sounds like after burning your tongue, you got a case of glossitis. This condition is an inflammation of the tongue that usually appears because of an infection like scarlet fever, tongue piercing, and even from burns as has happened in your case. There is usually no need to treat this condition at all when it comes from the burns of hot coffee. This is because the damage to the tongue is at the uppermost level and therefore not that severe.
What is very important to note is that right now your tongue is raw and inflamed. When you drink any hot drink that is above a certain temperature, the temperature and pain receptors immediately signal to the brain that cellular damage is imminent. If not for this reflex reaction, you would burn every single tissue from your mouth to your stomach opening the way for infections and a much more serious discomfort. Whatever area did touch the liquid however, was damaged at a cellular level and even that is a trigger for inflammation. Inflammation is the body’s emergency response to injury, infection, and allergy. It is an essential response to protect the body from further cell death and also to start the process of counter attack led by the white blood cells of the body. Typical signs of inflammation are a swelling, mucus production, and increased blood flow.
Since the area in question is your tongue, healing is a very difficult process unlike on a surface like the skin. Since the mouth is always wet, there is no dry medium to allow the remaining cells to create a protective wall immediately. One of the first things to do is to create this medium. Depending on which part of the tongue was burnt, dry it by forcing cool air on it – much like you would suck in a liquid through a straw. Try to fight the urge to wet it for at least two minutes. After this, you need to limit the movement of the tongue. Any ulcer medicines and gels can be applied before you go to bed to ensure some relief. Avoid all kinds of spicy food and food that is warmer than the temperature of your tongue. A lot of healing depends on the mucus secreted in your mouth; unfortunately, this very secretion is also a medium for bacteria to infect if you do not maintain oral hygiene. Despite the pain, use a mouthwash during this time to ensure that you get to all the possible troublesome bacteria.