What Causes Pain,swelling And Lack Of Moment In My Neck After An Injury?

I had an object fall and hit me on top of the head. They checked my head and jaw, but now my neck is starting to hurt. The range of movement has greatly decreased and the pain has increased. The right front side of my neck is swollen but i a do not have any pain there. This has been going on for 3 to 4 weeks. I have been to see doctors but i am getting worried because no one has given me an answer. What would be causing this?