What did I do to my head/neck?

I was playing a friendly game ov volleyball and I dove for it, but something compelled me to look up at the sky, at which point my body was travelling downwards and my head went all the way back (which it normally cannot comfortably do but slowly, very slowly and carefully) and it did this very quickly.  I heard a rather loud crack, similar to if I cracked all of my knuckles at once. I felt it at the base of my skull and it hurt for two seconds about so I rubbed it, naturally, and it went away. Now, it is 5 something in the morning and I have a headache right in the same area.

I am officially terrified because earlier this night I sounded like a drunk person when trying to form a sentence out loud. Granted I am very tired and I was conscious of the fact that my mouth was tired as well, but I was not very coordinated in a speaking sense. Everything else for the most part is fine as far as I can tell through the fatigue of only sleeping for 4 hours.

[selmaS]

  U could have sustained whip lash from that type of move...do go to the Dr and get a MRI or a X ray to see if nething was  done that can cause issues going forward,.

Do post updates.

[Moonlightwriter]

Well the headache went away and no further pain has bothered me, but I am still wary of reinjuring it, or injuring it further. I may get it checked out just to be sure.

[selmaS]

  Glad u r feeling better : )