CBD Oil and swish in your mouth. No sodas, no citric juice, avoid alcohol. Good mouth care with alcohol free mouthwash. Tom's is great! Use crushed ice to numb it; but the biggest part is what you put in your mouth. During flare ups eat soft food. Protein shakes. Complex B vitamins. Gabapentin. Opioids if unbearable and you don't have an addiction issue. There are prescription mouthwashes with numbing your physician can prescribe. See a naturopath. See a nutritionist.