I've prescribed a formula called a "magic swizzle" or "benadryl swizzle" for patients in acute mouth pain from herpatic stomatitis or apthous ulcers (canker sores). Its one part benadryl, one part viscous lidocaine, and one part Maalox or kaopectate. Most pharmacist know the recipe and it may not even need a prescription. It will help the symptoms buy not the source. Here is some more information if it pertains. Hope you get some help if you can't find anyone to call it in, send my a pm.
http://www.mssm.edu/msjournal/65/05_miy.pdf