I would suggest you see an oral surgeon for a consult. I do not have enough information about you, age,medical history,etc, to give you an opinion.
another off the wall thing is are you male and youve had oral sex recently? i only ask because yeast can creat a horrible burning pain! good luck
A few ideas and certainly not the only ones but I have read that nutritional deficiencies and hormonal imbalances can cause this.
I have heard this being referred to as "burning mouth syndrom."