Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain in case if you have pain and swelling in front of the ear and pain on chewing can be due to infection in 
parotid gland that is a major 
salivary gland..
As it is only on one side it can be most commonly due to bacterial infection..
Although it can also be due to viral infection caused by 
Mumps virus but it is commonly bilateral that is involving parotid glands on both left and right side..
I would suggest you to consult an Otolaryngologist and get evaluated and a thorough clinical evaluation and investigations like 
x ray or 
MRI Scan of the gland,Blood tests, salivary 
amylase can help in diagnosis and treatment can be planned accordingly..
In case of bacterial infection you can be advised antibiotics, anti inflammatory painkiller like 
Advil and 
Acetaminophen and also do cool compresses over the swelling..
In case if viral infection is the diagnosis it commonly resolves within a week and you have to take symptomatic treatment to alleviate the symptoms like Acetaminophen, do cool compresses and drink plenty of fluids and take ample of rest..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.