put table salt directly on it and also rinse area with salt water solution. Also rinse area with a strong mouthwash.
Ok, if you have clove, preferably ground clove (if not take whole clove and smash it up as good as you can), you want about a teaspoon of clove. Get some toothpaste about the size of a dime, then mash the clove and toothpaste together until they are blended completely. Then take that and put it into where the area of pain is. Try your hardest to know mess with it, or put water, saliva, or anything else wet on it. You want it to basically bond with the gum and tooth. Let it work it's magic. If you have to spit, please do not swallow and just spit into a sink, toilet, trash whatever. Clove is not dangerous in that amount to swallow, but it's unpleasant. After about 15 minutes, it should really really help with the pain.
Good luck till tomorrow.