Hi,
This could be mastoiditis, cervical lymphadenopathy or parotitis.
Have you seen an ENT specialist or your doctor for your symptoms? Do you have any associated symptoms of pain, discharge, fever, etc?
'Mastoiditis is an infection of the mastoid process, the portion of the temporal bone of the skull that is behind the ear. It is usually caused by untreated acute otitis media (middle ear infection) .'
You could read more about the condition at the following links -
http://en.wikipedia.org/wiki/Mastoidectomy
and
http://www.emedicine.com/emerg/topic306.htm
Let us know about how you are doing and if you have any other doubts.
Post us about what your doctor advises.
Regards.
sounds like a lymph node, they will swell and get tender if a infection and bug bites in or around that area will cause it to swell, you are fine. They can take quite a while to go done.