Hi.. 
Welcome to HEALTHCARE MAGIC.. 
I have gone through your query and can understand your concerns..  
As per your complain it seems that swollen duct of 
Salivary Gland and swollen tender gland under the jaw that seems probably be due to infection in the Submandibular Salivary Gland also know as Sialoadenosis..
I would suggest you to consult an Oral Physician and get evaluated and a clinical evaluation, 
x Ray or MRI and saliva culture can be advised for confirmation..
You can be advised a course of antibiotics like 
Augmentin, anti inflammatory painkiller like 
Ibuprofen and serratiopeptidases..
Doing cool compresses over the swelling can relieve..
Drink.plenty of water..
Chew sugar free chewing gum..
Massage the gland gently with fingers..
 Hope this information helps..  
Thanks and regards. 
Dr.Honey Nandwani Arora.