Okay. When a person has dry mouth and swelling of one side near the jaw, an obstructed salivary gland is a real possibility. The most common cause of obstruction is a stone (much like a kidney stone, or gallstone), but there are other possibilities. An infection -- usually bacterial -- can also cause swelling on one side, and bacteria can complicate an obstruction.
Swelling in one parotid gland is a reason to see your doctor sooner than later; understanding the cause is critical so that you can get prompt, appropriate treatment.
Just one more question:
Do you have heart, kidney, or liver failure?