It doesn’t seem logical that a tongue piercing would be the cause of this condition. Burning mouth syndrome may just go away on its own down the road. There are many possible causes for your condition. One common cause is a vitamin deficiency particularly iron, zinc, and all the B vitamins which blood tests can help rule this out by going to a Ear, Nose, and Throat doctor. This condition can be difficult to treat. Feel free to e-mail me since I have some experience and knowledge on the subject that can be of some benefit to you.