Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain pain under the ear can be due to a number of causes like dental infection, 
impacted wisdom tooth, infection related to 
Parotid gland, 
ear infection while it can also be due to jaw joint but in this case pain will also be in the area inform of ear and pain will be elicited on chewing and opening and closing mouth..
As there is salty taste in mouth there is a possibility that there is dental infection leading to pus formation and swelling..
I would suggest you to consult an Oral Physician and get evaluated and a thorough clinical evaluation and investigations like 
ORTHOPANTOMOGRAM or OPG that is a full mouth x ray, MRI SCAN etc can help in diagnosis and treatment can be done accordingly..
As of now you can take anti-inflammatory painkillers like Ibuprofen..
Do cool compresses over the swelling..
Take a 
soft diet.. 
Do warm saline gargles and gargle with antiseptic mouthwash...
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.