Hey dear
First of all you have a very Poor Oral hygiene. If it is causing by any sharp edgevof truth you must go to your nearby dentist to flatten the sharp edge or if there is nothing in the teeth it’s a tongue lesion,the differential diagnosis is a atropic glossitis.
Next Steps
First of all you must clean your tongue and observe if you feel any burning sensation when ever you take food particularly hot &spicy food.
Health Tips
Don’t left it un treated .Because repeated it injury from any teeth or false teeth may cause a fatal result. You must go to your near about dentist and get a thorough examination of your entire oral cavity .as it is seen in the picture I will say don’t left it .proper treatment in proper time will resolve it itself.Maintain proper oral hygiene.In case of any assistance contact me for a better consultation .
thank you