The episode that knocked you to the floor happened to me when I herniatd a disk. Did they even bother to do an MRI? If not, they should have!!! They should have done SOME tests, for pete's sakes! Sounds like they didn't do anything!
The cervical injection sounds miserable. did you call your doc about the swelling, etc? If not, I would. In the meantime, put ice on it to get the swelling down.
Keep us posted, will you. You're sure having a rough time. God bless. Hugs, Lee