The back left of my tongue and left side of neck are in throbbing pain. what could be wrong and how do i treat this?

Dental\Medical: Without actually being able to examine you and get some more information, we can't diagnose such symptoms over the internet. This may be a dental problem, a medical problem, or perhaps even both. You will need to see a physician and\or a dentist.

See dentist: There are a number of possibilities. You need to see a dentist for an evaluation. This is not something you can treat yourself.