Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concern... As per your complain sand paper like feeling inside mouth can be due to a few common conditions like Dry mouth, allergic reaction to any medication of food products, due to chemical or thermal burns. At times it can be due to formation of small sores either caused by viral infection [herpes] or due to canker sores.. Nothing to worry consult an Oral Physician and get evaluated and treatment can be planned according to the cause.. The swollen vein under the tongue can be an infected mucous cyst or mucocele or can be a traumatic ulcer. Do warm saline gargles for faster resolution.. You can also apply a numbing gel containing Lignocaine over it to prevent discomfort.. Swelling under jaw can be due to obstruction in the duct of the salivary gland caused by formation of crystalline stones from minerals present in saliva.. You are advised to suck on more of sour candies and drink plenty of water as these measures will increase saliva flow and the stones can at times gets flushed off with saliva.. But if it does not happen surgical removal of stones has to be done.. It should also be taken care of and should not be left untreated.. Hope this information helps.. Thanks and regards.. Dr.Honey Nandwani Arora.