you have taken something really hot which has caused burns on the ridges.
apply oral gel on the ridges and do warm water rinses 3-4 times a day.this will help in healing faster.
gel will help to numb the ridges and you will not feel pain while taking your meals.
Try salt with water
You probably ate something that irritated it, and made it raw with your tongue. If it persists, go see the doctor.