I am so sorry that this additional problem has come up. Some people bite their nails, others their cuticals. I don't know how to help, but I do understand OCD when a person is in severe pain. My mother did something like that by "picking" at her legs when she was in pain.
If this really is this bad, that you can't stop. Please tell you doctor. You have anxiety of that much I am sure of. I just don't want it to lead to another medical conditon. Your pain management needs to get better. When you want to hurt one part, because the other part hurts so badly, this needs to be addressed with someone who can help with OCD. You already know how much I care about you. Please keep in touch with me and let me know if there is anything Ican say or do to help you. I know there are others who suffer with horrible anxiety and pain together, and do have some control now with the right medical intervention. The mouth is such a sensitive area, you could give yourself an oral infection which you do not want. I am in your corner always, and will pray for you. ginnie