I've had nothing but problems with neck since i fell four years ago. lately i literally don't feel like i can hold my head up. very scary. what cause?

If you are having a: hard time holding your head up, you need to be examined immediately. Is this because of severe pain or weakness? I don't like the sound of that since you are also reporting hand weakness. When was the last time you got imaging of the C-spine stenosis? Looks like you are in physical therapy and getting steroid shots for the neck pain. Tell your docs about the neck weakness today. They'll work it up