Getting rid of pain underneath my tongue?

Chances are that it is simply an ulcer. Ulcers are white (yellow or green if affected by bacteria) spots you receive in your mouth. Most common reason for getting them is a sudden change in hormone levels, or stress.

It will hurt like the dickens, but the easiest way to get rid of them is to take a pinch of salt and sprinkle it directly on the sore, it helps to clean the area of bacteria, since you cant use antiseptics in the mouth. It should be gone in a day or two.

If it worsens, then I would be concerned and see a doctor.

Good Luck!

Yes, it could be some form of disease u got from kissing...
Maybe u don't brush well?
And believe it or not, you could have bit it in your sleep and it became infected?

In any case, mix a glass of water using 1 part hydrogen peroxide and 8 parts clear water. Gargle with this as long and deep as possible. DO NOT swallow. Repeat a couple times a day, slosh it around the tongue and by the 3rd day if it is not gone, see your doctor. K? Be cool now.

it's a map tongue, because of your lack of vitamin. try eating some livers of animals