Pinched Nerve?

On Saturday I completed my first century ride with no problems in terms of tiring out.  However, my shoulder was extremely stiff and felt a lot of pain.  Mostly sharp pain on the back of the shoulder where it meets the neck.  I finished the race and the next day this area was tight.  I went to a massage therapist to see if she could work it out and left with what appears to be nerve pain but I'm not sure how to address it or what it is. 

Everytime I turn my head left (my neck doesnt feel stiff at all) I feel a sharp pop that shoots down my back (straight down from the point where the back of your shoulder meets your neck (trapezius?).  It doesnt go down my spine, just straight down from the where the shoulder meets the neck.  And it isn't a POP...it feels like it, but I know it isn't a typical "pop like you would hear  when you crack a knuckle or somethign else.