Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain it seems that a sore spot under the tongue that is present on the right side with bruised underside of tongue can be due to causes like a traumatic/apthous ulcer, broken blood vessel,
hematoma etc..
Brusied appearrence can be due to burning with some hot food, allergies,
dry mouth etc..
You need not to worry as nothing looks serious..
You can start taking a Vitamin B complex tablet for a week.
Do warm saline gargles.
Do cool water rinses.
Avoid spicy, hard and sharp foods..
Take a soft and bland diet and drink plenty of water..
You can apply Lignocaine gel over the sore spot..
In case of no improvement in a week consult an Oral Physician and get evaluated..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.