Facial pain and "drooping"

I had a traumatic injury to the Left side of my face November 2009 - was struck with a fist. Initially had
large amount of swelling, black eye, bruising that extended into upper lip and neck area. Also developed smaller black eye type bruising of right eye.  Bruising has resolved, but pain continues.  There is also a sensation of fullness or swelling below the left eye. Pain along the left "cheek bone" and below it is stinging and burning in sensation- area is extremely sensitive to touch, and pain is exacerbated by Cold temperatures.  
Over the last 3 weeks or so, have now noticed a slight "drooping" of the left side of the face- most obvious at the left side of the lip area.  When I am very tired it feels like I have difficulty enunciating words, as if I am not moving the left side of my mouth quite right. My family says it sounds like I am slurring my words.
Please help! :-)