what can I put on the sore on my tongue

Make a mouthwash by adding 10 drops of tea tree oil in 1/3 cup of water. Swish this mouthwash for about 30 seconds, then spit it out. This will help to heal the sore.
Mix 1 teaspoon of honey with 1/4 teaspoon turmeric, and rub it on the sore.